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Pacemaker 1.1



Clusters from Scratch
=====================


Creating Active/Passive and Active/Active Clusters on Fedora
------------------------------------------------------------

Edition 5


Andrew Beekhof

Primary author Red Hatandrew@beekhof.net


Raoul Scarazzini

Italian translation rasca@miamammausalinux.org


Dan Frîncu

Romanian translation df.cluster@gmail.com

------------------------------------------------------------------------



Legal Notice
============

Copyright © 2012 Andrew Beekhof This material may only be distributed
subject to the terms and conditions set forth in the GNU Free
Documentation License (GFDL), V1.2 or later (the latest version is
presently available at http://www.gnu.org/licenses/fdl.txt).

Abstract

The purpose of this document is to provide a start-to-finish guide to
building an example active/passive cluster with Pacemaker and show how it
can be converted to an active/active one. The example cluster will use:

  1.  Fedora 17 as the host operating system

  2.  Corosync to provide messaging and membership services,

  3.  Pacemaker to perform resource management,

  4.  DRBD as a cost-effective alternative to shared storage,

  5.  GFS2 as the cluster filesystem (in active/active mode)

Given the graphical nature of the Fedora install process, a number of
screenshots are included. However the guide is primarily composed of
commands, the reasons for executing them and their expected outputs.

------------------------------------------------------------------------

Preface

      1. Document Conventions

            1.1. Typographic Conventions

            1.2. Pull-quote Conventions

            1.3. Notes and Warnings

      2. We Need Feedback!

1. Read-Me-First

      1.1. The Scope of this Document

      1.2. What Is Pacemaker?

      1.3. Pacemaker Architecture

            1.3.1. Internal Components

      1.4. Types of Pacemaker Clusters

2. Installation

      2.1. OS Installation

      2.2. Post Installation Tasks

            2.2.1. Networking

            2.2.2. Leaving the Console

            2.2.3. Security Shortcuts

            2.2.4. Short Node Names

            2.2.5. NTP

      2.3. Before You Continue

            2.3.1. Finalize Networking

            2.3.2. Configure SSH

      2.4. Cluster Software Installation

            2.4.1. Install the Cluster Software

            2.4.2. Install the Cluster Management Software

      2.5. Setup

            2.5.1. Enable pcs Daemon

            2.5.2. Configuring Corosync

3. Pacemaker Tools

      3.1. Using Pacemaker Tools

4. Verify Cluster Installation

      4.1. Start the Cluster

      4.2. Verify Corosync Installation

      4.3. Verify Pacemaker Installation

5. Creating an Active/Passive Cluster

      5.1. Exploring the Existing Configuration

      5.2. Adding a Resource

      5.3. Perform a Failover

            5.3.1. Quorum and Two-Node Clusters

            5.3.2. Prevent Resources from Moving after Recovery

6. Apache - Adding More Services

      6.1. Forward

      6.2. Installation

      6.3. Preparation

      6.4. Enable the Apache status URL

      6.5. Update the Configuration

      6.6. Ensuring Resources Run on the Same Host

      6.7. Controlling Resource Start/Stop Ordering

      6.8. Specifying a Preferred Location

      6.9. Manually Moving Resources Around the Cluster

            6.9.1. Giving Control Back to the Cluster

7. Replicated Storage with DRBD

      7.1. Background

      7.2. Install the DRBD Packages

      7.3. Configure DRBD

            7.3.1. Create A Partition for DRBD

            7.3.2. Write the DRBD Config

            7.3.3. Initialize and Load DRBD

            7.3.4. Populate DRBD with Data

      7.4. Configure the Cluster for DRBD

            7.4.1. Testing Migration

8. Conversion to Active/Active

      8.1. Requirements

            8.1.1. Installing the required Software

      8.2. Create a GFS2 Filesystem

            8.2.1. Preparation

            8.2.2. Create and Populate an GFS2 Partition

      8.3. Reconfigure the Cluster for GFS2

      8.4. Reconfigure Pacemaker for Active/Active

            8.4.1. Testing Recovery

9. Configure STONITH

      9.1. What Is STONITH

      9.2. What STONITH Device Should You Use

      9.3. Configuring STONITH

      9.4. Example

A. Configuration Recap

      A.1. Final Cluster Configuration

      A.2. Node List

      A.3. Cluster Options

      A.4. Resources

            A.4.1. Default Options

            A.4.2. Fencing

            A.4.3. Service Address

            A.4.4. DRBD - Shared Storage

            A.4.5. Cluster Filesystem

            A.4.6. Apache

B. Sample Corosync Configuration

C. Further Reading

D. Revision History

Index



Preface
=======


1. Document Conventions
-----------------------

1.1. Typographic Conventions

1.2. Pull-quote Conventions

1.3. Notes and Warnings

This manual uses several conventions to highlight certain words and
phrases and draw attention to specific pieces of information. In PDF and
paper editions, this manual uses typefaces drawn from the Liberation
Fonts set. The Liberation Fonts set is also used in HTML editions if the
set is installed on your system. If not, alternative but equivalent
typefaces are displayed. Note: Red Hat Enterprise Linux 5 and later
includes the Liberation Fonts set by default.


1.1. Typographic Conventions

Four typographic conventions are used to call attention to specific words
and phrases. These conventions, and the circumstances they apply to, are
as follows. Mono-spaced Bold Used to highlight system input, including
shell commands, file names and paths. Also used to highlight keycaps and
key combinations. For example:

  To see the contents of the file my_next_bestselling_novel in your
  current working directory, enter the cat my_next_bestselling_novel
  command at the shell prompt and press Enter to execute the command.

The above includes a file name, a shell command and a keycap, all
presented in mono-spaced bold and all distinguishable thanks to context.
Key combinations can be distinguished from keycaps by the hyphen
connecting each part of a key combination. For example:

  Press Enter to execute the command. Press Ctrl+Alt+F2 to switch to
  the first virtual terminal. Press Ctrl+Alt+F1 to return to your
  X-Windows session.

The first paragraph highlights the particular keycap to press. The second
highlights two key combinations (each a set of three keycaps with each
set pressed simultaneously). If source code is discussed, class names,
methods, functions, variable names and returned values mentioned within a
paragraph will be presented as above, in mono-spaced bold. For example:

  File-related classes include filesystem for file systems, file for
  files, and dir for directories. Each class has its own associated set
  of permissions.

Proportional Bold This denotes words or phrases encountered on a system,
including application names; dialog box text; labeled buttons; check-box
and radio button labels; menu titles and sub-menu titles. For example:

  Choose System → Preferences → Mouse from the main menu bar to launch
  Mouse Preferences. In the Buttons tab, click the Left-handed mouse
  check box and click Close to switch the primary mouse button from the
  left to the right (making the mouse suitable for use in the left
  hand). To insert a special character into a gedit file, choose
  Applications → Accessories → Character Map from the main menu bar.
  Next, choose Search → Find… from the Character Map menu bar, type the
  name of the character in the Search field and click Next. The
  character you sought will be highlighted in the Character Table.
  Double-click this highlighted character to place it in the Text to
  copy field and then click the Copy button. Now switch back to your
  document and choose Edit → Paste from the gedit menu bar.

The above text includes application names; system-wide menu names and
items; application-specific menu names; and buttons and text found within
a GUI interface, all presented in proportional bold and all
distinguishable by context. Mono-spaced Bold Italic or Proportional Bold
Italic Whether mono-spaced bold or proportional bold, the addition of
italics indicates replaceable or variable text. Italics denotes text you
do not input literally or displayed text that changes depending on
circumstance. For example:

  To connect to a remote machine using ssh, type ssh username@domain.name
  at a shell prompt. If the remote machine is example.com and your
  username on that machine is john, type ssh john@example.com. The
  mount -o remount file-system command remounts the named file system.
  For example, to remount the /home file system, the command is mount
  -o remount /home. To see the version of a currently installed
  package, use the rpm -q package command. It will return a result as
  follows: package-version-release.

Note the words in bold italics above — username, domain.name,
file-system, package, version and release. Each word is a placeholder,
either for text you enter when issuing a command or for text displayed by
the system. Aside from standard usage for presenting the title of a work,
italics denotes the first use of a new and important term. For example:

  Publican is a DocBook publishing system.


1.2. Pull-quote Conventions

Terminal output and source code listings are set off visually from the
surrounding text. Output sent to a terminal is set in mono-spaced roman
and presented thus:

books        Desktop   documentation  drafts  mss    photos   stuff  svn
books_tests  Desktop1  downloads      images  notes  scripts  svgs

Source-code listings are also set in mono-spaced roman but add syntax
highlighting as follows:

package org.jboss.book.jca.ex1;
import javax.naming.InitialContext;
public class ExClient
{
   public static void main(String args[]) 
       throws Exception
   {
      InitialContext iniCtx = new InitialContext();
      Object         ref    = iniCtx.lookup("EchoBean");
      EchoHome       home   = (EchoHome) ref;
      Echo           echo   = home.create();

      System.out.println("Created Echo");

      System.out.println("Echo.echo('Hello') = " + echo.echo("Hello"));
   }
}


1.3. Notes and Warnings

Finally, we use three visual styles to draw attention to information that
might otherwise be overlooked.


Note
----

Notes are tips, shortcuts or alternative approaches to the task at hand.
Ignoring a note should have no negative consequences, but you might miss
out on a trick that makes your life easier.


Important
---------

Important boxes detail things that are easily missed: configuration
changes that only apply to the current session, or services that need
restarting before an update will apply. Ignoring a box labeled
'Important' will not cause data loss but may cause irritation and
frustration.


Warning
-------

Warnings should not be ignored. Ignoring warnings will most likely cause
data loss.


2. We Need Feedback!
--------------------

You should over ride this by creating your own local Feedback.xml file.



Chapter 1. Read-Me-First
========================

1.1. The Scope of this Document

1.2. What Is Pacemaker?

1.3. Pacemaker Architecture

      1.3.1. Internal Components

1.4. Types of Pacemaker Clusters


1.1. The Scope of this Document
-------------------------------

Computer clusters can be used to provide highly available services or
resources. The redundancy of multiple machines is used to guard against
failures of many types. This document will walk through the installation
and setup of simple clusters using the Fedora distribution, version 17.
The clusters described here will use Pacemaker and Corosync to provide
resource management and messaging. Required packages and modifications to
their configuration files are described along with the use of the
Pacemaker command line tool for generating the XML used for cluster
control. Pacemaker is a central component and provides the resource
management required in these systems. This management includes detecting
and recovering from the failure of various nodes, resources and services
under its control. When more in depth information is required and for
real world usage, please refer to the Pacemaker Explained manual.


1.2. What Is Pacemaker?
-----------------------

Pacemaker is a cluster resource manager. It achieves maximum availability
for your cluster services (aka. resources) by detecting and recovering
from node and resource-level failures by making use of the messaging and
membership capabilities provided by your preferred cluster infrastructure
(either Corosync or Heartbeat). Pacemaker’s key features include:

  *  Detection and recovery of node and service-level failures

  *  Storage agnostic, no requirement for shared storage

  *  Resource agnostic, anything that can be scripted can be clustered

  *  Supports STONITH for ensuring data integrity

  *  Supports large and small clusters

  *  Supports both quorate and resource driven clusters

  *  Supports practically any redundancy configuration

  *  Automatically replicated configuration that can be updated from any
    node

  *  Ability to specify cluster-wide service ordering, colocation and
    anti-colocation

  *  Support for advanced service types

      *  Clones: for services which need to be active on multiple nodes

      *  Multi-state: for services with multiple modes (eg. master/slave,
        primary/secondary)

  *  Unified, scriptable, cluster management tools.


1.3. Pacemaker Architecture
---------------------------

1.3.1. Internal Components

At the highest level, the cluster is made up of three pieces:

  *  Non-cluster aware components (illustrated in green). These pieces
    include the resources themselves, scripts that start, stop and
    monitor them, and also a local daemon that masks the differences
    between the different standards these scripts implement.

  *  Resource management Pacemaker provides the brain (illustrated in
    blue) that processes and reacts to events regarding the cluster.
    These events include nodes joining or leaving the cluster; resource
    events caused by failures, maintenance, scheduled activities; and
    other administrative actions. Pacemaker will compute the ideal state
    of the cluster and plot a path to achieve it after any of these
    events. This may include moving resources, stopping nodes and even
    forcing them offline with remote power switches.

  *  Low level infrastructure Corosync provides reliable messaging,
    membership and quorum information about the cluster (illustrated in
    red).

Conceptual overview of the cluster stack

Figure 1.1. Conceptual Stack Overview


When combined with Corosync, Pacemaker also supports popular open source
cluster filesystems. [1] Due to recent standardization within the cluster
filesystem community, they make use of a common distributed lock manager
which makes use of Corosync for its messaging capabilities and Pacemaker
for its membership (which nodes are up/down) and fencing services.
The Pacemaker StackThe Pacemaker stack when running on Corosync

Figure 1.2. The Pacemaker Stack


1.3.1. Internal Components

Pacemaker itself is composed of four key components (illustrated below in
the same color scheme as the previous diagram):

  *  CIB (aka. Cluster Information Base)

  *  CRMd (aka. Cluster Resource Management daemon)

  *  PEngine (aka. PE or Policy Engine)

  *  STONITHd

Subsystems of a Pacemaker cluster running on Corosync

Figure 1.3. Internal Components


The CIB uses XML to represent both the cluster’s configuration and
current state of all resources in the cluster. The contents of the CIB
are automatically kept in sync across the entire cluster and are used by
the PEngine to compute the ideal state of the cluster and how it should
be achieved. This list of instructions is then fed to the DC (Designated
Co-ordinator). Pacemaker centralizes all cluster decision making by
electing one of the CRMd instances to act as a master. Should the elected
CRMd process, or the node it is on, fail… a new one is quickly
established. The DC carries out the PEngine’s instructions in the
required order by passing them to either the LRMd (Local Resource
Management daemon) or CRMd peers on other nodes via the cluster messaging
infrastructure (which in turn passes them on to their LRMd process). The
peer nodes all report the results of their operations back to the DC and
based on the expected and actual results, will either execute any actions
that needed to wait for the previous one to complete, or abort processing
and ask the PEngine to recalculate the ideal cluster state based on the
unexpected results. In some cases, it may be necessary to power off nodes
in order to protect shared data or complete resource recovery. For this
Pacemaker comes with STONITHd. STONITH is an acronym for
Shoot-The-Other-Node-In-The-Head and is usually implemented with a remote
power switch. In Pacemaker, STONITH devices are modeled as resources (and
configured in the CIB) to enable them to be easily monitored for failure,
however STONITHd takes care of understanding the STONITH topology such
that its clients simply request a node be fenced and it does the rest.


1.4. Types of Pacemaker Clusters
--------------------------------

Pacemaker makes no assumptions about your environment, this allows it to
support practically any redundancy configuration including Active/Active,
Active/Passive, N+1, N+M, N-to-1 and N-to-N. In this document we will
focus on the setup of a highly available Apache web server with an
Active/Passive cluster using DRBD and Ext4 to store data. Then, we will
upgrade this cluster to Active/Active using GFS2.
Two-node Active/Passive clusters using Pacemaker and DRBD are a cost-effective solution for many High Availability situations

Figure 1.4. Active/Passive Redundancy


When shared storage is available, every node can potentially be used for failover. Pacemaker can even run multiple copies of services to spread out the workload

Figure 1.5. N to N Redundancy



------------------------------------------------------------------------

[1] Even though Pacemaker also supports Heartbeat, the filesystems need
to use the stack for messaging and membership and Corosync seems to be
what they’re standardizing on. Technically it would be possible for them
to support Heartbeat as well, however there seems little interest in
this.



Chapter 2. Installation
=======================

2.1. OS Installation

2.2. Post Installation Tasks

      2.2.1. Networking

      2.2.2. Leaving the Console

      2.2.3. Security Shortcuts

      2.2.4. Short Node Names

      2.2.5. NTP

2.3. Before You Continue

      2.3.1. Finalize Networking

      2.3.2. Configure SSH

2.4. Cluster Software Installation

      2.4.1. Install the Cluster Software

      2.4.2. Install the Cluster Management Software

2.5. Setup

      2.5.1. Enable pcs Daemon

      2.5.2. Configuring Corosync


2.1. OS Installation
--------------------

Detailed instructions for installing Fedora are available at
http://docs.fedoraproject.org/en-US/Fedora/17/html/Installation_Guide/ in
a number of languages. The abbreviated version is as follows… Point your
browser to http://fedoraproject.org/en/get-fedora-all, locate the Install
Media section and download the install DVD that matches your hardware.
Burn the disk image to a DVD [2] and boot from it, or use the image to
boot a virtual machine. After clicking through the welcome screen, select
your language, keyboard layout [3] and storage type [4] Assign your
machine a host name. [5] I happen to control the clusterlabs.org domain
name, so I will use that here.


Important
---------

Do not accept the default network settings. Cluster machines should never
obtain an IP address via DHCP. When you are presented with the Configure
Network advanced option, select that option before continuing with the
installation process to specify a fixed IPv4 address for System eth0. Be
sure to also enter the Routes section and add an entry for your default
gateway. Custom network settings If you miss this step, this can easily
be configured after installation. You will have to navigate to system
settings and select network. From there you can select what device to
configure. You will then be prompted to indicate the machine’s physical
location [6] and to supply a root password. [7] Now select where you want
Fedora installed. [8] As I don’t care about any existing data, I will
accept the default and allow Fedora to use the complete drive.


Important
---------

By default Fedora uses LVM for partitioning which allows us to
dynamically change the amount of space allocated to a given partition.
However, by default it also allocates all free space to the / (aka. root)
partition which cannot be dynamically reduced in size (dynamic increases
are fine by-the-way). So if you plan on following the DRBD or GFS2
portions of this guide, you should reserve at least 1Gb of space on each
machine from which to create a shared volume. To do so select the Review
and modify partitioning layout checkbox before clicking Next. You will
then be given an opportunity to reduce the size of the root partition.
Next choose which software should be installed. [9] Change the selection
to Minimal so that we see everything that gets installed. Don’t enable
updates yet, we’ll do that (and install any extra software we need)
later. After you click next, Fedora will begin installing. Go grab
something to drink, this may take a while. Once the node reboots, you’ll
see a (possibly mangled) login prompt on the console. Login using root
and the password you created earlier. Initial Console


Note
----

From here on in we’re going to be working exclusively from the terminal.


2.2. Post Installation Tasks
----------------------------

2.2.1. Networking

2.2.2. Leaving the Console

2.2.3. Security Shortcuts

2.2.4. Short Node Names

2.2.5. NTP


2.2.1. Networking

Bring up the network and ensure it starts at boot

# service network start
# chkconfig network on

Check the machine has the static IP address you configured earlier

# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 52:54:00:d7:d6:08 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.101/24 brd 192.168.122.255 scope global eth0
    inet6 fe80::5054:ff:fed7:d608/64 scope link
       valid_lft forever preferred_lft forever

Now check the default route setting:

[root@pcmk-1 ~]# ip route
default via 192.168.122.1 dev eth0
192.168.122.0/24 dev eth0  proto kernel  scope link  src 192.168.122.101

If there is no line beginning with default via, then you may need to add
a line such as

GATEWAY=192.168.122.1

to /etc/sysconfig/network and restart the network. Now check for
connectivity to the outside world. Start small by testing if we can read
the gateway we configured.

# ping -c 1 192.168.122.1
PING 192.168.122.1 (192.168.122.1) 56(84) bytes of data.
64 bytes from 192.168.122.1: icmp_req=1 ttl=64 time=0.249 ms

--- 192.168.122.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.249/0.249/0.249/0.000 ms

Now try something external, choose a location you know will be available.

# ping -c 1 www.google.com
PING www.l.google.com (173.194.72.106) 56(84) bytes of data.
64 bytes from tf-in-f106.1e100.net (173.194.72.106): icmp_req=1 ttl=41 time=167 ms

--- www.l.google.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 167.618/167.618/167.618/0.000 ms


2.2.2. Leaving the Console

The console isn’t a very friendly place to work from, we will now switch
to accessing the machine remotely via SSH where we can use copy&paste
etc. First we check we can see the newly installed at all:

beekhof@f16 ~ # ping -c 1 192.168.122.101
PING 192.168.122.101 (192.168.122.101) 56(84) bytes of data.
64 bytes from 192.168.122.101: icmp_req=1 ttl=64 time=1.01 ms

--- 192.168.122.101 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 1.012/1.012/1.012/0.000 ms

Next we login via SSH

beekhof@f16 ~ # ssh -l root 192.168.122.11
root@192.168.122.11's password:
Last login: Fri Mar 30 19:41:19 2012 from 192.168.122.1
[root@pcmk-1 ~]#


2.2.3. Security Shortcuts

To simplify this guide and focus on the aspects directly connected to
clustering, we will now disable the machine’s firewall and SELinux
installation.


Warning
-------

Both of these actions create significant security issues and should not
be performed on machines that will be exposed to the outside world.


Important
---------

TODO: Create an Appendix that deals with (at least) re-enabling the firewall.

# setenforce 0# sed -i.bak "s/SELINUX=enforcing/SELINUX=permissive/g" /etc/selinux/config# systemctl disable iptables.servicerm '/etc/systemd/system/basic.target.wants/iptables.service'# systemctl stop iptables.service


2.2.4. Short Node Names

During installation, we filled in the machine’s fully qualifier domain
name (FQDN) which can be rather long when it appears in cluster logs and
status output. See for yourself how the machine identifies itself:

# uname -npcmk-1.clusterlabs.org# dnsdomainnameclusterlabs.org

The output from the second command is fine, but we really don’t need the
domain name included in the basic host details. To address this, we need
to update /etc/sysconfig/network. This is what it should look like before
we start.

# cat /etc/sysconfig/networkNETWORKING=yesHOSTNAME=pcmk-1.clusterlabs.orgGATEWAY=192.168.122.1

All we need to do now is strip off the domain name portion, which is
stored elsewhere anyway.

 # sed -i.sed 's/\.[a-z].*//g' /etc/sysconfig/network

Now confirm the change was successful. The revised file contents should
look something like this.

# cat /etc/sysconfig/networkNETWORKING=yesHOSTNAME=pcmk-1GATEWAY=192.168.122.1

However we’re not finished. The machine wont normally see the shortened
host name until about it reboots, but we can force it to update.

# source /etc/sysconfig/network# hostname $HOSTNAME

Now check the machine is using the correct names

# uname -npcmk-1# dnsdomainnameclusterlabs.org


2.2.5. NTP

It is highly recommended to enable NTP on your cluster nodes. Doing so
ensures all nodes agree on the current time and makes reading log files
significantly easier. [10]


2.3. Before You Continue
------------------------

2.3.1. Finalize Networking

2.3.2. Configure SSH

Repeat the Installation steps so far, so that you have two Fedora nodes
ready to have the cluster software installed. For the purposes of this
document, the additional node is called pcmk-2 with address
192.168.122.102.


2.3.1. Finalize Networking

Confirm that you can communicate between the two new nodes:

# ping -c 3 192.168.122.102PING 192.168.122.102 (192.168.122.102) 56(84) bytes of data.
64 bytes from 192.168.122.102: icmp_seq=1 ttl=64 time=0.343 ms
64 bytes from 192.168.122.102: icmp_seq=2 ttl=64 time=0.402 ms
64 bytes from 192.168.122.102: icmp_seq=3 ttl=64 time=0.558 ms

--- 192.168.122.102 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.343/0.434/0.558/0.092 ms

Now we need to make sure we can communicate with the machines by their
name. If you have a DNS server, add additional entries for the two
machines. Otherwise, you’ll need to add the machines to /etc/hosts .
Below are the entries for my cluster nodes:

# grep pcmk /etc/hosts192.168.122.101 pcmk-1.clusterlabs.org pcmk-1
192.168.122.102 pcmk-2.clusterlabs.org pcmk-2

We can now verify the setup by again using ping:

# ping -c 3 pcmk-2PING pcmk-2.clusterlabs.org (192.168.122.101) 56(84) bytes of data.
64 bytes from pcmk-1.clusterlabs.org (192.168.122.101): icmp_seq=1 ttl=64 time=0.164 ms
64 bytes from pcmk-1.clusterlabs.org (192.168.122.101): icmp_seq=2 ttl=64 time=0.475 ms
64 bytes from pcmk-1.clusterlabs.org (192.168.122.101): icmp_seq=3 ttl=64 time=0.186 ms

--- pcmk-2.clusterlabs.org ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2001ms
rtt min/avg/max/mdev = 0.164/0.275/0.475/0.141 ms


2.3.2. Configure SSH

SSH is a convenient and secure way to copy files and perform commands
remotely. For the purposes of this guide, we will create a key without a
password (using the -N option) so that we can perform remote actions
without being prompted.


Warning
-------

Unprotected SSH keys, those without a password, are not recommended for
servers exposed to the outside world. We use them here only to simplify
the demo. Create a new key and allow anyone with that key to log in:

# ssh-keygen -t dsa -f ~/.ssh/id_dsa -N ""Generating public/private dsa key pair.
Your identification has been saved in /root/.ssh/id_dsa.
Your public key has been saved in /root/.ssh/id_dsa.pub.
The key fingerprint is:
91:09:5c:82:5a:6a:50:08:4e:b2:0c:62:de:cc:74:44 root@pcmk-1.clusterlabs.org

The key's randomart image is:+--[ DSA 1024]----+|==.ooEo..        ||X O + .o o       || * A    +        ||  +      .       || .      S        ||                 ||                 ||                 ||                 |+-----------------+# cp .ssh/id_dsa.pub .ssh/authorized_keys

Install the key on the other nodes and test that you can now run commands
remotely, without being prompted

# scp -r .ssh pcmk-2:The authenticity of host 'pcmk-2 (192.168.122.102)' can't be established.RSA key fingerprint is b1:2b:55:93:f1:d9:52:2b:0f:f2:8a:4e:ae:c6:7c:9a.Are you sure you want to continue connecting (yes/no)? yesWarning: Permanently added 'pcmk-2,192.168.122.102' (RSA) to the list of known hosts.root@pcmk-2's password:id_dsa.pub                           100%  616     0.6KB/s   00:00id_dsa                               100%  672     0.7KB/s   00:00
known_hosts                          100%  400     0.4KB/s   00:00
authorized_keys                      100%  616     0.6KB/s   00:00# ssh pcmk-2 -- uname -npcmk-2#


2.4. Cluster Software Installation
----------------------------------

2.4.1. Install the Cluster Software

2.4.2. Install the Cluster Management Software


2.4.1. Install the Cluster Software

Since version 12, Fedora comes with recent versions of everything you
need, so simply fire up the shell and run:

# yum install -y pacemaker corosyncfedora/metalink                                  |  38 kB     00:00
fedora                                           | 4.2 kB     00:00
fedora/primary_db                                |  14 MB     00:21
updates/metalink                                 | 2.7 kB     00:00
updates                                          | 2.6 kB     00:00
updates/primary_db                               | 1.2 kB     00:00
updates-testing/metalink                         |  28 kB     00:00
updates-testing                                  | 4.5 kB     00:00
updates-testing/primary_db                       | 4.5 MB     00:12
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package corosync.x86_64 0:1.99.9-1.fc17 will be installed
--> Processing Dependency: corosynclib = 1.99.9-1.fc17 for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libxslt for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libvotequorum.so.5(COROSYNC_VOTEQUORUM_1.0)(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libquorum.so.5(COROSYNC_QUORUM_1.0)(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libcpg.so.4(COROSYNC_CPG_1.0)(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libcmap.so.4(COROSYNC_CMAP_1.0)(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libcfg.so.6(COROSYNC_CFG_0.82)(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libvotequorum.so.5()(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libtotem_pg.so.5()(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libquorum.so.5()(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libqb.so.0()(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libnetsnmp.so.30()(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libcpg.so.4()(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libcorosync_common.so.4()(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libcmap.so.4()(64bit) for package: corosync-1.99.9-1.fc17.x86_64
--> Processing Dependency: libcfg.so.6()(64bit) for package: corosync-1.99.9-1.fc17.x86_64
---> Package pacemaker.x86_64 0:1.1.7-2.fc17 will be installed
--> Processing Dependency: pacemaker-libs = 1.1.7-2.fc17 for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: pacemaker-cluster-libs = 1.1.7-2.fc17 for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: pacemaker-cli = 1.1.7-2.fc17 for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: resource-agents for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: perl(Getopt::Long) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libgnutls.so.26(GNUTLS_1_4)(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: cluster-glue for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: /usr/bin/perl for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libtransitioner.so.1()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libstonithd.so.1()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libstonith.so.1()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libplumb.so.2()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libpils.so.2()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libpengine.so.3()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libpe_status.so.3()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libpe_rules.so.2()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libltdl.so.7()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: liblrm.so.2()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libgnutls.so.26()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libcrmcommon.so.2()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libcrmcluster.so.1()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Processing Dependency: libcib.so.1()(64bit) for package: pacemaker-1.1.7-2.fc17.x86_64
--> Running transaction check
---> Package cluster-glue.x86_64 0:1.0.6-9.fc17.1 will be installed
--> Processing Dependency: perl-TimeDate for package: cluster-glue-1.0.6-9.fc17.1.x86_64
--> Processing Dependency: libOpenIPMIutils.so.0()(64bit) for package: cluster-glue-1.0.6-9.fc17.1.x86_64
--> Processing Dependency: libOpenIPMIposix.so.0()(64bit) for package: cluster-glue-1.0.6-9.fc17.1.x86_64
--> Processing Dependency: libOpenIPMI.so.0()(64bit) for package: cluster-glue-1.0.6-9.fc17.1.x86_64
---> Package cluster-glue-libs.x86_64 0:1.0.6-9.fc17.1 will be installed
---> Package corosynclib.x86_64 0:1.99.9-1.fc17 will be installed
--> Processing Dependency: librdmacm.so.1(RDMACM_1.0)(64bit) for package: corosynclib-1.99.9-1.fc17.x86_64
--> Processing Dependency: libibverbs.so.1(IBVERBS_1.1)(64bit) for package: corosynclib-1.99.9-1.fc17.x86_64
--> Processing Dependency: libibverbs.so.1(IBVERBS_1.0)(64bit) for package: corosynclib-1.99.9-1.fc17.x86_64
--> Processing Dependency: librdmacm.so.1()(64bit) for package: corosynclib-1.99.9-1.fc17.x86_64
--> Processing Dependency: libibverbs.so.1()(64bit) for package: corosynclib-1.99.9-1.fc17.x86_64
---> Package gnutls.x86_64 0:2.12.17-1.fc17 will be installed
--> Processing Dependency: libtasn1.so.3(LIBTASN1_0_3)(64bit) for package: gnutls-2.12.17-1.fc17.x86_64
--> Processing Dependency: libtasn1.so.3()(64bit) for package: gnutls-2.12.17-1.fc17.x86_64
--> Processing Dependency: libp11-kit.so.0()(64bit) for package: gnutls-2.12.17-1.fc17.x86_64
---> Package libqb.x86_64 0:0.11.1-1.fc17 will be installed
---> Package libtool-ltdl.x86_64 0:2.4.2-3.fc17 will be installed
---> Package libxslt.x86_64 0:1.1.26-9.fc17 will be installed
---> Package net-snmp-libs.x86_64 1:5.7.1-4.fc17 will be installed
---> Package pacemaker-cli.x86_64 0:1.1.7-2.fc17 will be installed
---> Package pacemaker-cluster-libs.x86_64 0:1.1.7-2.fc17 will be installed
---> Package pacemaker-libs.x86_64 0:1.1.7-2.fc17 will be installed
---> Package perl.x86_64 4:5.14.2-211.fc17 will be installed
--> Processing Dependency: perl-libs = 4:5.14.2-211.fc17 for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(threads::shared) >= 1.21 for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(Socket) >= 1.3 for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(Scalar::Util) >= 1.10 for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(File::Spec) >= 0.8 for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl-macros for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl-libs for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(threads::shared) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(threads) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(Socket) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(Scalar::Util) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(Pod::Simple) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(Module::Pluggable) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(List::Util) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(File::Spec::Unix) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(File::Spec::Functions) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(File::Spec) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(Cwd) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: perl(Carp) for package: 4:perl-5.14.2-211.fc17.x86_64
--> Processing Dependency: libperl.so()(64bit) for package: 4:perl-5.14.2-211.fc17.x86_64
---> Package resource-agents.x86_64 0:3.9.2-2.fc17.1 will be installed
--> Processing Dependency: /usr/sbin/rpc.nfsd for package: resource-agents-3.9.2-2.fc17.1.x86_64
--> Processing Dependency: /usr/sbin/rpc.mountd for package: resource-agents-3.9.2-2.fc17.1.x86_64
--> Processing Dependency: /usr/sbin/ethtool for package: resource-agents-3.9.2-2.fc17.1.x86_64
--> Processing Dependency: /sbin/rpc.statd for package: resource-agents-3.9.2-2.fc17.1.x86_64
--> Processing Dependency: /sbin/quotaon for package: resource-agents-3.9.2-2.fc17.1.x86_64
--> Processing Dependency: /sbin/quotacheck for package: resource-agents-3.9.2-2.fc17.1.x86_64
--> Processing Dependency: /sbin/mount.nfs4 for package: resource-agents-3.9.2-2.fc17.1.x86_64
--> Processing Dependency: /sbin/mount.nfs for package: resource-agents-3.9.2-2.fc17.1.x86_64
--> Processing Dependency: /sbin/mount.cifs for package: resource-agents-3.9.2-2.fc17.1.x86_64
--> Processing Dependency: /sbin/fsck.xfs for package: resource-agents-3.9.2-2.fc17.1.x86_64
--> Processing Dependency: libnet.so.1()(64bit) for package: resource-agents-3.9.2-2.fc17.1.x86_64
--> Running transaction check
---> Package OpenIPMI-libs.x86_64 0:2.0.18-13.fc17 will be installed
---> Package cifs-utils.x86_64 0:5.3-2.fc17 will be installed
--> Processing Dependency: libtalloc.so.2(TALLOC_2.0.2)(64bit) for package: cifs-utils-5.3-2.fc17.x86_64
--> Processing Dependency: keyutils for package: cifs-utils-5.3-2.fc17.x86_64
--> Processing Dependency: libwbclient.so.0()(64bit) for package: cifs-utils-5.3-2.fc17.x86_64
--> Processing Dependency: libtalloc.so.2()(64bit) for package: cifs-utils-5.3-2.fc17.x86_64
---> Package ethtool.x86_64 2:3.2-2.fc17 will be installed
---> Package libibverbs.x86_64 0:1.1.6-2.fc17 will be installed
---> Package libnet.x86_64 0:1.1.5-3.fc17 will be installed
---> Package librdmacm.x86_64 0:1.0.15-1.fc17 will be installed
---> Package libtasn1.x86_64 0:2.12-1.fc17 will be installed
---> Package nfs-utils.x86_64 1:1.2.5-12.fc17 will be installed
--> Processing Dependency: rpcbind for package: 1:nfs-utils-1.2.5-12.fc17.x86_64
--> Processing Dependency: libtirpc for package: 1:nfs-utils-1.2.5-12.fc17.x86_64
--> Processing Dependency: libnfsidmap for package: 1:nfs-utils-1.2.5-12.fc17.x86_64
--> Processing Dependency: libgssglue.so.1(libgssapi_CITI_2)(64bit) for package: 1:nfs-utils-1.2.5-12.fc17.x86_64
--> Processing Dependency: libgssglue for package: 1:nfs-utils-1.2.5-12.fc17.x86_64
--> Processing Dependency: libevent for package: 1:nfs-utils-1.2.5-12.fc17.x86_64
--> Processing Dependency: libtirpc.so.1()(64bit) for package: 1:nfs-utils-1.2.5-12.fc17.x86_64
--> Processing Dependency: libnfsidmap.so.0()(64bit) for package: 1:nfs-utils-1.2.5-12.fc17.x86_64
--> Processing Dependency: libgssglue.so.1()(64bit) for package: 1:nfs-utils-1.2.5-12.fc17.x86_64
--> Processing Dependency: libevent-2.0.so.5()(64bit) for package: 1:nfs-utils-1.2.5-12.fc17.x86_64
---> Package p11-kit.x86_64 0:0.12-1.fc17 will be installed
---> Package perl-Carp.noarch 0:1.22-2.fc17 will be installed
---> Package perl-Module-Pluggable.noarch 1:3.90-211.fc17 will be installed
---> Package perl-PathTools.x86_64 0:3.33-211.fc17 will be installed
---> Package perl-Pod-Simple.noarch 1:3.16-211.fc17 will be installed
--> Processing Dependency: perl(Pod::Escapes) >= 1.04 for package: 1:perl-Pod-Simple-3.16-211.fc17.noarch
---> Package perl-Scalar-List-Utils.x86_64 0:1.25-1.fc17 will be installed
---> Package perl-Socket.x86_64 0:2.001-1.fc17 will be installed
---> Package perl-TimeDate.noarch 1:1.20-6.fc17 will be installed
---> Package perl-libs.x86_64 4:5.14.2-211.fc17 will be installed
---> Package perl-macros.x86_64 4:5.14.2-211.fc17 will be installed
---> Package perl-threads.x86_64 0:1.86-2.fc17 will be installed
---> Package perl-threads-shared.x86_64 0:1.40-2.fc17 will be installed
---> Package quota.x86_64 1:4.00-3.fc17 will be installed
--> Processing Dependency: quota-nls = 1:4.00-3.fc17 for package: 1:quota-4.00-3.fc17.x86_64
--> Processing Dependency: tcp_wrappers for package: 1:quota-4.00-3.fc17.x86_64
---> Package xfsprogs.x86_64 0:3.1.8-1.fc17 will be installed
--> Running transaction check
---> Package keyutils.x86_64 0:1.5.5-2.fc17 will be installed
---> Package libevent.x86_64 0:2.0.14-2.fc17 will be installed
---> Package libgssglue.x86_64 0:0.3-1.fc17 will be installed
---> Package libnfsidmap.x86_64 0:0.25-1.fc17 will be installed
---> Package libtalloc.x86_64 0:2.0.7-4.fc17 will be installed
---> Package libtirpc.x86_64 0:0.2.2-2.1.fc17 will be installed
---> Package libwbclient.x86_64 1:3.6.3-81.fc17.1 will be installed
---> Package perl-Pod-Escapes.noarch 1:1.04-211.fc17 will be installed
---> Package quota-nls.noarch 1:4.00-3.fc17 will be installed
---> Package rpcbind.x86_64 0:0.2.0-16.fc17 will be installed
---> Package tcp_wrappers.x86_64 0:7.6-69.fc17 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

 ==============================================================================================
 Package                        Arch      Version             Repository            Size=====================================================================================
Installing:
 corosync                       x86_64    1.99.9-1.fc17       updates-testing   159 k
 pacemaker                      x86_64    1.1.7-2.fc17        updates-testing   362 k
Installing for dependencies:
 OpenIPMI-libs                  x86_64    2.0.18-13.fc17      fedora            466 k
 cifs-utils                     x86_64    5.3-2.fc17          updates-testing    66 k
 cluster-glue                   x86_64    1.0.6-9.fc17.1      fedora            229 k
 cluster-glue-libs              x86_64    1.0.6-9.fc17.1      fedora            121 k
 corosynclib                    x86_64    1.99.9-1.fc17       updates-testing    96 k
 ethtool                        x86_64    2:3.2-2.fc17        fedora             94 k
 gnutls                         x86_64    2.12.17-1.fc17      fedora            385 k
 keyutils                       x86_64    1.5.5-2.fc17        fedora             49 k
 libevent                       x86_64    2.0.14-2.fc17       fedora            160 k
 libgssglue                     x86_64    0.3-1.fc17          fedora             24 k
 libibverbs                     x86_64    1.1.6-2.fc17        fedora             44 k
 libnet                         x86_64    1.1.5-3.fc17        fedora             54 k
 libnfsidmap                    x86_64    0.25-1.fc17         fedora             34 k
 libqb                          x86_64    0.11.1-1.fc17       updates-testing    68 k
 librdmacm                      x86_64    1.0.15-1.fc17       fedora             27 k
 libtalloc                      x86_64    2.0.7-4.fc17        fedora             22 k
 libtasn1                       x86_64    2.12-1.fc17         updates-testing   319 k
 libtirpc                       x86_64    0.2.2-2.1.fc17      fedora             78 k
 libtool-ltdl                   x86_64    2.4.2-3.fc17        fedora             45 k
 libwbclient                    x86_64    1:3.6.3-81.fc17.1   updates-testing    68 k
 libxslt                        x86_64    1.1.26-9.fc17       fedora            416 k
 net-snmp-libs                  x86_64    1:5.7.1-4.fc17      fedora            713 k
 nfs-utils                      x86_64    1:1.2.5-12.fc17     fedora            311 k
 p11-kit                        x86_64    0.12-1.fc17         updates-testing    36 k
 pacemaker-cli                  x86_64    1.1.7-2.fc17        updates-testing   368 k
 pacemaker-cluster-libs         x86_64    1.1.7-2.fc17        updates-testing    77 k
 pacemaker-libs                 x86_64    1.1.7-2.fc17        updates-testing   322 k
 perl                           x86_64    4:5.14.2-211.fc17   fedora             10 M
 perl-Carp                      noarch    1.22-2.fc17         fedora             17 k
 perl-Module-Pluggable          noarch    1:3.90-211.fc17     fedora             47 k
 perl-PathTools                 x86_64    3.33-211.fc17       fedora            105 k
 perl-Pod-Escapes               noarch    1:1.04-211.fc17     fedora             40 k
 perl-Pod-Simple                noarch    1:3.16-211.fc17     fedora            223 k
 perl-Scalar-List-Utils         x86_64    1.25-1.fc17         updates-testing    33 k
 perl-Socket                    x86_64    2.001-1.fc17        updates-testing    44 k
 perl-TimeDate                  noarch    1:1.20-6.fc17       fedora             43 k
 perl-libs                      x86_64    4:5.14.2-211.fc17   fedora            628 k
 perl-macros                    x86_64    4:5.14.2-211.fc17   fedora             32 k
 perl-threads                   x86_64    1.86-2.fc17         fedora             47 k
 perl-threads-shared            x86_64    1.40-2.fc17         fedora             36 k
 quota                          x86_64    1:4.00-3.fc17       fedora            160 k
 quota-nls                      noarch    1:4.00-3.fc17       fedora             74 k
 resource-agents                x86_64    3.9.2-2.fc17.1      fedora            466 k
 rpcbind                        x86_64    0.2.0-16.fc17       fedora             52 k
 tcp_wrappers                   x86_64    7.6-69.fc17         fedora             72 k
 xfsprogs                       x86_64    3.1.8-1.fc17        updates-testing   715 k

Transaction Summary
=====================================================================================Install  2 Packages (+46 Dependent packages)
Total download size: 18 M
Installed size: 59 M
Downloading Packages:(1/48): OpenIPMI-libs-2.0.18-13.fc17.x86_64.rpm                       | 466 kB     00:00
warning: rpmts_HdrFromFdno: Header V3 RSA/SHA256 Signature, key ID 1aca3465: NOKEY
Public key for OpenIPMI-libs-2.0.18-13.fc17.x86_64.rpm is not installed(2/48): cifs-utils-5.3-2.fc17.x86_64.rpm                              |  66 kB     00:01
Public key for cifs-utils-5.3-2.fc17.x86_64.rpm is not installed(3/48): cluster-glue-1.0.6-9.fc17.1.x86_64.rpm                        | 229 kB     00:00(4/48): cluster-glue-libs-1.0.6-9.fc17.1.x86_64.rpm                   | 121 kB     00:00(5/48): corosync-1.99.9-1.fc17.x86_64.rpm                             | 159 kB     00:01(6/48): corosynclib-1.99.9-1.fc17.x86_64.rpm                          |  96 kB     00:00(7/48): ethtool-3.2-2.fc17.x86_64.rpm                                 |  94 kB     00:00(8/48): gnutls-2.12.17-1.fc17.x86_64.rpm                              | 385 kB     00:00(9/48): keyutils-1.5.5-2.fc17.x86_64.rpm                              |  49 kB     00:00(10/48): libevent-2.0.14-2.fc17.x86_64.rpm                            | 160 kB     00:00(11/48): libgssglue-0.3-1.fc17.x86_64.rpm                             |  24 kB     00:00(12/48): libibverbs-1.1.6-2.fc17.x86_64.rpm                           |  44 kB     00:00(13/48): libnet-1.1.5-3.fc17.x86_64.rpm                               |  54 kB     00:00(14/48): libnfsidmap-0.25-1.fc17.x86_64.rpm                           |  34 kB     00:00(15/48): libqb-0.11.1-1.fc17.x86_64.rpm                               |  68 kB     00:01(16/48): librdmacm-1.0.15-1.fc17.x86_64.rpm                           |  27 kB     00:00(17/48): libtalloc-2.0.7-4.fc17.x86_64.rpm                            |  22 kB     00:00(18/48): libtasn1-2.12-1.fc17.x86_64.rpm                              | 319 kB     00:02(19/48): libtirpc-0.2.2-2.1.fc17.x86_64.rpm                           |  78 kB     00:00(20/48): libtool-ltdl-2.4.2-3.fc17.x86_64.rpm                         |  45 kB     00:00(21/48): libwbclient-3.6.3-81.fc17.1.x86_64.rpm                       |  68 kB     00:00(22/48): libxslt-1.1.26-9.fc17.x86_64.rpm                             | 416 kB     00:00(23/48): net-snmp-libs-5.7.1-4.fc17.x86_64.rpm                        | 713 kB     00:01(24/48): nfs-utils-1.2.5-12.fc17.x86_64.rpm                           | 311 kB     00:00(25/48): p11-kit-0.12-1.fc17.x86_64.rpm                               |  36 kB     00:01(26/48): pacemaker-1.1.7-2.fc17.x86_64.rpm                            | 362 kB     00:02(27/48): pacemaker-cli-1.1.7-2.fc17.x86_64.rpm                        | 368 kB     00:02(28/48): pacemaker-cluster-libs-1.1.7-2.fc17.x86_64.rpm               |  77 kB     00:00(29/48): pacemaker-libs-1.1.7-2.fc17.x86_64.rpm                       | 322 kB     00:01(30/48): perl-5.14.2-211.fc17.x86_64.rpm                              |  10 MB     00:15(31/48): perl-Carp-1.22-2.fc17.noarch.rpm                             |  17 kB     00:00(32/48): perl-Module-Pluggable-3.90-211.fc17.noarch.rpm               |  47 kB     00:00(33/48): perl-PathTools-3.33-211.fc17.x86_64.rpm                      | 105 kB     00:00(34/48): perl-Pod-Escapes-1.04-211.fc17.noarch.rpm                    |  40 kB     00:00(35/48): perl-Pod-Simple-3.16-211.fc17.noarch.rpm                     | 223 kB     00:00(36/48): perl-Scalar-List-Utils-1.25-1.fc17.x86_64.rpm                |  33 kB     00:01(37/48): perl-Socket-2.001-1.fc17.x86_64.rpm                          |  44 kB     00:00(38/48): perl-TimeDate-1.20-6.fc17.noarch.rpm                         |  43 kB     00:00(39/48): perl-libs-5.14.2-211.fc17.x86_64.rpm                         | 628 kB     00:00(40/48): perl-macros-5.14.2-211.fc17.x86_64.rpm                       |  32 kB     00:00(41/48): perl-threads-1.86-2.fc17.x86_64.rpm                          |  47 kB     00:00(42/48): perl-threads-shared-1.40-2.fc17.x86_64.rpm                   |  36 kB     00:00(43/48): quota-4.00-3.fc17.x86_64.rpm                                 | 160 kB     00:00(44/48): quota-nls-4.00-3.fc17.noarch.rpm                             |  74 kB     00:00(45/48): resource-agents-3.9.2-2.fc17.1.x86_64.rpm                    | 466 kB     00:00(46/48): rpcbind-0.2.0-16.fc17.x86_64.rpm                             |  52 kB     00:00(47/48): tcp_wrappers-7.6-69.fc17.x86_64.rpm                          |  72 kB     00:00(48/48): xfsprogs-3.1.8-1.fc17.x86_64.rpm                             | 715 kB     00:03
 ---------------------------------------------------------------------------------------
Total                                                        333 kB/s |  18 MB     00:55
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-x86_64
Importing GPG key 0x1ACA3465:
 Userid     : "Fedora (17) <fedora@fedoraproject.org>" Fingerprint: cac4 3fb7 74a4 a673 d81c 5de7 50e9 4c99 1aca 3465
 Package    : fedora-release-17-0.8.noarch (@anaconda-0) From       : /etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-x86_64
Running Transaction Check
Running Transaction TestTransaction Test Succeeded
Running Transaction
  Installing : libqb-0.11.1-1.fc17.x86_64                                         1/48
  Installing : libtool-ltdl-2.4.2-3.fc17.x86_64                                   2/48
  Installing : cluster-glue-libs-1.0.6-9.fc17.1.x86_64                            3/48
  Installing : libxslt-1.1.26-9.fc17.x86_64                                       4/48
  Installing : 1:perl-Pod-Escapes-1.04-211.fc17.noarch                            5/48
  Installing : perl-threads-1.86-2.fc17.x86_64                                    6/48
  Installing : 4:perl-macros-5.14.2-211.fc17.x86_64                               7/48
  Installing : 1:perl-Pod-Simple-3.16-211.fc17.noarch                             8/48
  Installing : perl-Socket-2.001-1.fc17.x86_64                                    9/48
  Installing : perl-Carp-1.22-2.fc17.noarch                                      10/48
  Installing : 4:perl-libs-5.14.2-211.fc17.x86_64                                11/48
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  Installing : perl-Scalar-List-Utils-1.25-1.fc17.x86_64                         13/48
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  Installing : 4:perl-5.14.2-211.fc17.x86_64                                     16/48
  Installing : libibverbs-1.1.6-2.fc17.x86_64                                    17/48
  Installing : keyutils-1.5.5-2.fc17.x86_64                                      18/48
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  Installing : libtirpc-0.2.2-2.1.fc17.x86_64                                    20/48
  Installing : 1:net-snmp-libs-5.7.1-4.fc17.x86_64                               21/48
  Installing : rpcbind-0.2.0-16.fc17.x86_64                                      22/48
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  Installing : corosynclib-1.99.9-1.fc17.x86_64                                  24/48
  Installing : corosync-1.99.9-1.fc17.x86_64                                     25/48
error reading information on service corosync: No such file or directory
  Installing : 1:perl-TimeDate-1.20-6.fc17.noarch                                26/48
  Installing : 1:quota-nls-4.00-3.fc17.noarch                                    27/48
  Installing : tcp_wrappers-7.6-69.fc17.x86_64                                   28/48
  Installing : 1:quota-4.00-3.fc17.x86_64                                        29/48
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  Installing : 1:libwbclient-3.6.3-81.fc17.1.x86_64                              31/48
  Installing : libnet-1.1.5-3.fc17.x86_64                                        32/48
  Installing : 2:ethtool-3.2-2.fc17.x86_64                                       33/48
  Installing : libevent-2.0.14-2.fc17.x86_64                                     34/48
  Installing : 1:nfs-utils-1.2.5-12.fc17.x86_64                                  35/48
  Installing : libtalloc-2.0.7-4.fc17.x86_64                                     36/48
  Installing : cifs-utils-5.3-2.fc17.x86_64                                      37/48
  Installing : libtasn1-2.12-1.fc17.x86_64                                       38/48
  Installing : OpenIPMI-libs-2.0.18-13.fc17.x86_64                               39/48
  Installing : cluster-glue-1.0.6-9.fc17.1.x86_64                                40/48
  Installing : p11-kit-0.12-1.fc17.x86_64                                        41/48
  Installing : gnutls-2.12.17-1.fc17.x86_64                                      42/48
  Installing : pacemaker-libs-1.1.7-2.fc17.x86_64                                43/48
  Installing : pacemaker-cluster-libs-1.1.7-2.fc17.x86_64                        44/48
  Installing : pacemaker-cli-1.1.7-2.fc17.x86_64                                 45/48
  Installing : xfsprogs-3.1.8-1.fc17.x86_64                                      46/48
  Installing : resource-agents-3.9.2-2.fc17.1.x86_64                             47/48
  Installing : pacemaker-1.1.7-2.fc17.x86_64                                     48/48
  Verifying  : xfsprogs-3.1.8-1.fc17.x86_64                                       1/48
  Verifying  : 1:net-snmp-libs-5.7.1-4.fc17.x86_64                                2/48
  Verifying  : corosync-1.99.9-1.fc17.x86_64                                      3/48
  Verifying  : cluster-glue-1.0.6-9.fc17.1.x86_64                                 4/48
  Verifying  : perl-PathTools-3.33-211.fc17.x86_64                                5/48
  Verifying  : p11-kit-0.12-1.fc17.x86_64                                         6/48
  Verifying  : 1:perl-Pod-Simple-3.16-211.fc17.noarch                             7/48
  Verifying  : OpenIPMI-libs-2.0.18-13.fc17.x86_64                                8/48
  Verifying  : libtasn1-2.12-1.fc17.x86_64                                        9/48
  Verifying  : perl-threads-1.86-2.fc17.x86_64                                   10/48
  Verifying  : 1:perl-Pod-Escapes-1.04-211.fc17.noarch                           11/48
  Verifying  : pacemaker-1.1.7-2.fc17.x86_64                                     12/48
  Verifying  : 4:perl-5.14.2-211.fc17.x86_64                                     13/48
  Verifying  : gnutls-2.12.17-1.fc17.x86_64                                      14/48
  Verifying  : perl-threads-shared-1.40-2.fc17.x86_64                            15/48
  Verifying  : 4:perl-macros-5.14.2-211.fc17.x86_64                              16/48
  Verifying  : 1:perl-Module-Pluggable-3.90-211.fc17.noarch                      17/48
  Verifying  : 1:nfs-utils-1.2.5-12.fc17.x86_64                                  18/48
  Verifying  : cluster-glue-libs-1.0.6-9.fc17.1.x86_64                           19/48
  Verifying  : pacemaker-libs-1.1.7-2.fc17.x86_64                                20/48
  Verifying  : libtalloc-2.0.7-4.fc17.x86_64                                     21/48
  Verifying  : libevent-2.0.14-2.fc17.x86_64                                     22/48
  Verifying  : perl-Socket-2.001-1.fc17.x86_64                                   23/48
  Verifying  : libgssglue-0.3-1.fc17.x86_64                                      24/48
  Verifying  : perl-Carp-1.22-2.fc17.noarch                                      25/48
  Verifying  : libtirpc-0.2.2-2.1.fc17.x86_64                                    26/48
  Verifying  : 2:ethtool-3.2-2.fc17.x86_64                                       27/48
  Verifying  : 4:perl-libs-5.14.2-211.fc17.x86_64                                28/48
  Verifying  : libxslt-1.1.26-9.fc17.x86_64                                      29/48
  Verifying  : rpcbind-0.2.0-16.fc17.x86_64                                      30/48
  Verifying  : librdmacm-1.0.15-1.fc17.x86_64                                    31/48
  Verifying  : resource-agents-3.9.2-2.fc17.1.x86_64                             32/48
  Verifying  : 1:quota-4.00-3.fc17.x86_64                                        33/48
  Verifying  : 1:perl-TimeDate-1.20-6.fc17.noarch                                34/48
  Verifying  : perl-Scalar-List-Utils-1.25-1.fc17.x86_64                         35/48
  Verifying  : libtool-ltdl-2.4.2-3.fc17.x86_64                                  36/48
  Verifying  : pacemaker-cluster-libs-1.1.7-2.fc17.x86_64                        37/48
  Verifying  : cifs-utils-5.3-2.fc17.x86_64                                      38/48
  Verifying  : libnet-1.1.5-3.fc17.x86_64                                        39/48
  Verifying  : corosynclib-1.99.9-1.fc17.x86_64                                  40/48
  Verifying  : libqb-0.11.1-1.fc17.x86_64                                        41/48
  Verifying  : 1:libwbclient-3.6.3-81.fc17.1.x86_64                              42/48
  Verifying  : libnfsidmap-0.25-1.fc17.x86_64                                    43/48
  Verifying  : tcp_wrappers-7.6-69.fc17.x86_64                                   44/48
  Verifying  : keyutils-1.5.5-2.fc17.x86_64                                      45/48
  Verifying  : libibverbs-1.1.6-2.fc17.x86_64                                    46/48
  Verifying  : 1:quota-nls-4.00-3.fc17.noarch                                    47/48
  Verifying  : pacemaker-cli-1.1.7-2.fc17.x86_64                                 48/48

Installed:
  corosync.x86_64 0:1.99.9-1.fc17           pacemaker.x86_64 0:1.1.7-2.fc17

Dependency Installed:
  OpenIPMI-libs.x86_64 0:2.0.18-13.fc17     cifs-utils.x86_64 0:5.3-2.fc17
  cluster-glue.x86_64 0:1.0.6-9.fc17.1      cluster-glue-libs.x86_64 0:1.0.6-9.fc17.1
  corosynclib.x86_64 0:1.99.9-1.fc17        ethtool.x86_64 2:3.2-2.fc17
  gnutls.x86_64 0:2.12.17-1.fc17            keyutils.x86_64 0:1.5.5-2.fc17
  libevent.x86_64 0:2.0.14-2.fc17           libgssglue.x86_64 0:0.3-1.fc17
  libibverbs.x86_64 0:1.1.6-2.fc17          libnet.x86_64 0:1.1.5-3.fc17
  libnfsidmap.x86_64 0:0.25-1.fc17          libqb.x86_64 0:0.11.1-1.fc17
  librdmacm.x86_64 0:1.0.15-1.fc17          libtalloc.x86_64 0:2.0.7-4.fc17
  libtasn1.x86_64 0:2.12-1.fc17             libtirpc.x86_64 0:0.2.2-2.1.fc17
  libtool-ltdl.x86_64 0:2.4.2-3.fc17        libwbclient.x86_64 1:3.6.3-81.fc17.1
  libxslt.x86_64 0:1.1.26-9.fc17            net-snmp-libs.x86_64 1:5.7.1-4.fc17
  nfs-utils.x86_64 1:1.2.5-12.fc17          p11-kit.x86_64 0:0.12-1.fc17
  pacemaker-cli.x86_64 0:1.1.7-2.fc17       pacemaker-cluster-libs.x86_64 0:1.1.7-2.fc17
  pacemaker-libs.x86_64 0:1.1.7-2.fc17      perl.x86_64 4:5.14.2-211.fc17
  perl-Carp.noarch 0:1.22-2.fc17            perl-Module-Pluggable.noarch 1:3.90-211.fc17
  perl-PathTools.x86_64 0:3.33-211.fc17     perl-Pod-Escapes.noarch 1:1.04-211.fc17
  perl-Pod-Simple.noarch 1:3.16-211.fc17    perl-Scalar-List-Utils.x86_64 0:1.25-1.fc17
  perl-Socket.x86_64 0:2.001-1.fc17         perl-TimeDate.noarch 1:1.20-6.fc17
  perl-libs.x86_64 4:5.14.2-211.fc17        perl-macros.x86_64 4:5.14.2-211.fc17
  perl-threads.x86_64 0:1.86-2.fc17         perl-threads-shared.x86_64 0:1.40-2.fc17
  quota.x86_64 1:4.00-3.fc17                quota-nls.noarch 1:4.00-3.fc17
  resource-agents.x86_64 0:3.9.2-2.fc17.1   rpcbind.x86_64 0:0.2.0-16.fc17
  tcp_wrappers.x86_64 0:7.6-69.fc17         xfsprogs.x86_64 0:3.1.8-1.fc17
Complete!
[root@pcmk-1 ~]#

Now install the cluster software on the second node.


2.4.2. Install the Cluster Management Software

The pcs cli command coupled with the pcs daemon creates a cluster
management system capable of managing all aspects of the cluster stack
across all nodes from a single location.

# yum install -y pcs

Make sure to install the pcs packages on both nodes.


2.5. Setup
----------

2.5.1. Enable pcs Daemon

2.5.2. Configuring Corosync


2.5.1. Enable pcs Daemon

Before the cluster can be configured, the pcs daemon must be started and
enabled to boot on startup on each node. This daemon works with the pcs
cli command to manage syncing the corosync configuration across all the
nodes in the cluster. Start and enable the daemon by issuing the
following commands on each node.

# systemctl start pcsd.service# systemctl enable pcsd.service

Now setup a common pcs user account on each node in the cluster using the
pcs_passwd command. In the example below, the user account pcmk is
created. You will be asked to supply a password (or supply one with the
-p option). Make sure the username and password is consistent across all
the nodes.

# pcs_passwd pcmkpassword:

The pcs daemon account is required on each node to enable remote pcs
command authentication. While the pcs cli command can be used locally
without setting up a pcs daemon user account, access to pcs features that
require access to remote nodes (such as syncing the corosync config, or
starting/stopping the cluster on remote nodes) will be unavailable. This
tutorial will make use of these remote access commands.


2.5.2. Configuring Corosync

In the past, at this point in the tutorial an explanation of how to
configure and propagate corosync’s /etc/corosync.conf file would be
necessary. Using pcs with the pcs daemon greatly simplifies this process
by generating the corosync.conf across all the nodes in the cluster with
a single command. The only thing required to achieve this is to
authenticate as the pcs user pcmk on one of the nodes in the cluster, and
then issue the pcs cluster setup command with a list of all the node
names in the cluster.

# pcs cluster auth pcmk-1 pcmk-2Username: pcmk
Password:
pcmk-1: Authorized
pcmk-2: Authorized
# pcs cluster setup mycluster pcmk-1 pcmk-2pcmk-1: Succeeded
pcmk-2: Succeeded

That’s it. Corosync is configured across the cluster. If you received an
authorization error for either of those commands, make sure you setup the
pcmk user account using the pcs_passwd command on every node in the
cluster with the same password. The final /etc/corosync.conf
configuration on each node should look something like the sample in
Appendix B, Sample Corosync Configuration.


Important
---------

Pacemaker used to obtain membership and quorum from a custom Corosync
plugin. This plugin also had the capability to start Pacemaker
automatically when Corosync was started. Neither behavior is possible
with Corosync 2.0 and beyond as support for plugins was removed. Instead,
Pacemaker must be started as a separate job/initscript. Also, since
Pacemaker made use of the plugin for message routing, a node using the
plugin (Corosync prior to 2.0) cannot talk to one that isn’t (Corosync
2.0+). Rolling upgrades between these versions are therefor not possible
and an alternate strategy [11] must be used.

------------------------------------------------------------------------

[2]
http://docs.fedoraproject.org/en-US/Fedora/16/html/Burning_ISO_images_to_disc/index.html
[3]
http://docs.fedoraproject.org/en-US/Fedora/16/html/Installation_Guide/sn-keyboard-x86.html
[4]
http://docs.fedoraproject.org/en-US/Fedora/16/html/Installation_Guide/Storage_Devices-x86.html
[5]
http://docs.fedoraproject.org/en-US/Fedora/16/html/Installation_Guide/sn-Netconfig-x86.html
[6]
http://docs.fedoraproject.org/en-US/Fedora/16/html/Installation_Guide/s1-timezone-x86.html
[7]
http://docs.fedoraproject.org/en-US/Fedora/16/html/Installation_Guide/sn-account_configuration-x86.html
[8]
http://docs.fedoraproject.org/en-US/Fedora/16/html/Installation_Guide/s1-diskpartsetup-x86.html
[9]
http://docs.fedoraproject.org/en-US/Fedora/16/html/Installation_Guide/s1-pkgselection-x86.html
[10]
http://docs.fedoraproject.org/en-US/Fedora/17/html-single/System_Administrators_Guide/index.html#ch-Configuring_the_Date_and_Time
[11]
http://www.clusterlabs.org/doc/en-US/Pacemaker/1.1/html/Pacemaker_Explained/ap-upgrade.html



Chapter 3. Pacemaker Tools
==========================

3.1. Using Pacemaker Tools


3.1. Using Pacemaker Tools
--------------------------

In the dark past, configuring Pacemaker required the administrator to
read and write XML. In true UNIX style, there were also a number of
different commands that specialized in different aspects of querying and
updating the cluster. All of that has been greatly simplified with the
creation of unified command-line shells (and GUIs) that hide all the
messy XML scaffolding. These shells take all the individual aspects
required for managing and configuring a cluster, and packs them into one
simple to use command line tool. They even allow you to queue up several
changes at once and commit them atomically. There are currently two
command-line shells that people use, pcs and the crm shell. This edition
of Clusters from Scratch is based on pcs. Start by taking some time to
familiarize yourself with what it can do.


Note
----

The two shells share many concepts but the scope, layout and syntax does
differ, so make sure you read the version of this guide that corresponds
to the software installed on your system.


Important
---------

Since pcs has the ability to manage all aspects of the cluster (both
corosync and pacemaker), it requires a specific cluster stack to be in
use, (corosync 2.0 with votequorum + Pacemaker version >= 1.8).

# pcsControl and configure pacemaker and corosync.

Options:
    -h          Display usage and exit    -f file     Perform actions on file instead of active CIB

Commands:
    resource    Manage cluster resources
    cluster     Configure cluster options and nodes
    stonith     Configure fence devices
    property    Set pacemaker properties
    constraint  Set resource constraints
    status      View cluster status

As you can see, the different aspects of cluster management are broken up
into categories: resource, cluster, stonith, property, constraint, and
status. To discover the functionality available in each of these
categories, one can issue the command pcs <category> help. Below is an
example of all the options available under the status category.

# pcs status helpUsage: pcs status [commands]...
View current cluster and resource status
Commands:
    status
        View all information about the cluster and resources

    status resources
        View current status of cluster resources

    status groups        View currently configured groups and their resources

    status cluster
        View current cluster status

    status corosync
        View current corosync status

    status nodes [corosync]
        View current status of nodes from pacemaker, or if corosync is
        specified, print nodes currently configured in corosync

    status actions
        View failed actions

    status pcsd <node> ...
        Show the current status of pcsd on the specified nodes

    status xml
        View xml version of status (output from crm_mon -r -1 -X)

Additionally, if you are interested in the Pacemaker version and
supported cluster stack(s) available with your current Pacemaker
installation, the pacemakerd --features option is available to you. #
pacemakerd --features


Note
----

If the SNMP and/or email options are not listed, then Pacemaker was not
built to support them. This may be by the choice of your distribution or
the required libraries may not have been available. Please contact
whoever supplied you with the packages for more details.



Chapter 4. Verify Cluster Installation
======================================

4.1. Start the Cluster

4.2. Verify Corosync Installation

4.3. Verify Pacemaker Installation


4.1. Start the Cluster
----------------------

Now that corosync is configured, it is time to start the cluster. The
command below will start corosync and pacemaker on both nodes in the
cluster. If you are issuing the start command from a different node than
the one you ran the pcs cluster auth command on earlier, you must
authenticate on current node you are logged into before you will be
allowed to start the cluster.

# pcs cluster start --allpcmk-1: Starting Cluster...
pcmk-2: Starting Cluster...

An alternative to using the pcs cluster startall command is to issue
either of the below commands on each node in the cluster by hand.

# pcs cluster startStarting Cluster...

or

# systemctl start corosync.service# systemctl start pacemaker.service


4.2. Verify Corosync Installation
---------------------------------

The first thing to check is if cluster communication is happy, for that
we use corosync-cfgtool.

# corosync-cfgtool -s
Printing ring status.
Local node ID 1
RING ID 0
        id      = 192.168.122.101
        status  = ring 0 active with no faults

We can see here that everything appears normal with our fixed IP address,
not a 127.0.0.x loopback address, listed as the id and no faults for the
status. If you see something different, you might want to start by
checking the node’s network, firewall and selinux configurations. Next we
check the membership and quorum APIs:

# corosync-cmapctl  | grep membersruntime.totem.pg.mrp.srp.members.1.ip (str) = r(0) ip(192.168.122.101)runtime.totem.pg.mrp.srp.members.1.join_count (u32) = 1
runtime.totem.pg.mrp.srp.members.1.status (str) = joined
runtime.totem.pg.mrp.srp.members.2.ip (str) = r(0) ip(192.168.122.102)runtime.totem.pg.mrp.srp.members.2.join_count (u32) = 1
runtime.totem.pg.mrp.srp.members.2.status (str) = joined
# pcs status corosyncMembership information
 --------------------------
    Nodeid      Votes Name
         1          1 pcmk-1
         2          1 pcmk-2

You should see both nodes have joined the cluster. All good!


4.3. Verify Pacemaker Installation
----------------------------------

Now that we have confirmed that Corosync is functional we can check the
rest of the stack. Pacemaker has already been started, so verify the
necessary processes are running.

# ps axf  PID TTY      STAT   TIME COMMAND    2 ?        S      0:00 [kthreadd]
...lots of processes...
28019 ?        Ssl    0:03 /usr/sbin/corosync
28047 ?        Ss     0:00 /usr/sbin/pacemakerd -f
28048 ?        Ss     0:00  \_ /usr/libexec/pacemaker/cib
28049 ?        Ss     0:00  \_ /usr/libexec/pacemaker/stonithd
28050 ?        Ss     0:00  \_ /usr/lib64/heartbeat/lrmd
28051 ?        Ss     0:00  \_ /usr/libexec/pacemaker/attrd
28052 ?        Ss     0:00  \_ /usr/libexec/pacemaker/pengine
28053 ?        Ss     0:00  \_ /usr/libexec/pacemaker/crmd

If that looks ok, check the pcs status output.

# pcs statusLast updated: Fri Sep 14 09:52:25 2012Last change: Fri Sep 14 09:51:55 2012 via crmd on pcmk-2
Stack: corosync
Current DC: pcmk-2 (2) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
0 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

Next, check for any ERRORs during startup - there shouldn’t be any.

# grep -i error /var/log/messages

Repeat these checks on the other node. The results should be the same.



Chapter 5. Creating an Active/Passive Cluster
=============================================

5.1. Exploring the Existing Configuration

5.2. Adding a Resource

5.3. Perform a Failover

      5.3.1. Quorum and Two-Node Clusters

      5.3.2. Prevent Resources from Moving after Recovery


5.1. Exploring the Existing Configuration
-----------------------------------------

When Pacemaker starts up, it automatically records the number and details
of the nodes in the cluster as well as which stack is being used and the
version of Pacemaker being used. This is what the base configuration
should look like.

# pcs statusLast updated: Fri Sep 14 10:12:01 2012Last change: Fri Sep 14 09:51:55 2012 via crmd on pcmk-2
Stack: corosync
Current DC: pcmk-1 (1) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
0 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

For those that are not of afraid of XML, you can see the raw cluster
configuration and status by using the pcs cluster cib command.

# pcs cluster cib<cib epoch="4" num_updates="19" admin_epoch="0" validate-with="pacemaker-1.2" crm_feature_set="3.0.6" update-origin="pcmk-1" update-client="crmd" cib-last-written="Wed Aug  1 16:08:52 2012" have-quorum="1" dc-uuid="1">  <configuration>    <crm_config>      <cluster_property_set id="cib-bootstrap-options">        <nvpair id="cib-bootstrap-options-dc-version" name="dc-version" value="1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0"/>        <nvpair id="cib-bootstrap-options-cluster-infrastructure" name="cluster-infrastructure" value="corosync"/>      </cluster_property_set>    </crm_config>    <nodes>      <node id="1" uname="pcmk-1" type="normal"/>      <node id="2" uname="pcmk-2" type="normal"/>    </nodes>    <resources/>    <constraints/>  </configuration>  <status>    <node_state id="2" uname="pcmk-2" ha="active" in_ccm="true" crmd="online" join="member" expected="member" crm-debug-origin="do_state_transition" shutdown="0">      <lrm id="2">        <lrm_resources/>      </lrm>      <transient_attributes id="2">        <instance_attributes id="status-2">          <nvpair id="status-2-probe_complete" name="probe_complete" value="true"/>        </instance_attributes>      </transient_attributes>    </node_state>    <node_state id="1" uname="pcmk-1" ha="active" in_ccm="true" crmd="online" join="member" expected="member" crm-debug-origin="do_state_transition" shutdown="0">      <lrm id="1">        <lrm_resources/>      </lrm>      <transient_attributes id="1">        <instance_attributes id="status-1">          <nvpair id="status-1-probe_complete" name="probe_complete" value="true"/>        </instance_attributes>      </transient_attributes>    </node_state>  </status></cib>

Before we make any changes, its a good idea to check the validity of the
configuration.

# crm_verify -L -V   error: unpack_resources: Resource start-up disabled since no STONITH resources have been defined
   error: unpack_resources: Either configure some or disable STONITH with the stonith-enabled option
   error: unpack_resources: NOTE: Clusters with shared data need STONITH to ensure data integrity
Errors found during check: config not valid
  -V may provide more details

As you can see, the tool has found some errors. In order to guarantee the
safety of your data [12] , the default for STONITH [13] in Pacemaker is
enabled. However it also knows when no STONITH configuration has been
supplied and reports this as a problem (since the cluster would not be
able to make progress if a situation requiring node fencing arose). For
now, we will disable this feature and configure it later in the
Configuring STONITH section. It is important to note that the use of
STONITH is highly encouraged, turning it off tells the cluster to simply
pretend that failed nodes are safely powered off. Some vendors will even
refuse to support clusters that have it disabled. To disable STONITH, we
set the stonith-enabled cluster option to false.

# pcs property set stonith-enabled=false# crm_verify -L

With the new cluster option set, the configuration is now valid.


Warning
-------

The use of stonith-enabled=false is completely inappropriate for a
production cluster. We use it here to defer the discussion of its
configuration which can differ widely from one installation to the next.
See Section 9.1, “What Is STONITH” for information on why STONITH is
important and details on how to configure it.


5.2. Adding a Resource
----------------------

The first thing we should do is configure an IP address. Regardless of
where the cluster service(s) are running, we need a consistent address to
contact them on. Here I will choose and add 192.168.122.120 as the
floating address, give it the imaginative name ClusterIP and tell the
cluster to check that its running every 30 seconds.


Important
---------

The chosen address must not be one already associated with a physical
node

# pcs resource create ClusterIP ocf:heartbeat:IPaddr2 \    ip=192.168.0.120 cidr_netmask=32 op monitor interval=30s

The other important piece of information here is ocf:heartbeat:IPaddr2.
This tells Pacemaker three things about the resource you want to add. The
first field, ocf, is the standard to which the resource script conforms
to and where to find it. The second field is specific to OCF resources
and tells the cluster which namespace to find the resource script in, in
this case heartbeat. The last field indicates the name of the resource
script. To obtain a list of the available resource standards (the ocf
part of ocf:heartbeat:IPaddr2), run

# pcs resource standardsocf
lsb
service
systemd
stonith

To obtain a list of the available ocf resource providers (the heartbeat
part of ocf:heartbeat:IPaddr2), run

# pcs resource providersheartbeat
linbit
pacemaker
redhat

Finally, if you want to see all the resource agents available for a
specific ocf provider (the IPaddr2 part of ocf:heartbeat:IPaddr2), run

# pcs resource agents ocf:heartbeatAoEtarget
AudibleAlarm
CTDB
ClusterMon
Delay
Dummy
.
. (skipping lots of resources to save space).
IPaddr2
.
.
.
symlink
syslog-ng
tomcat
vmware

Now verify that the IP resource has been added and display the cluster’s
status to see that it is now active.

# pcs statusLast updated: Fri Sep 14 10:17:00 2012Last change: Fri Sep 14 10:15:48 2012 via cibadmin on pcmk-1
Stack: corosync
Current DC: pcmk-1 (1) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
1 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-1


5.3. Perform a Failover
-----------------------

5.3.1. Quorum and Two-Node Clusters

5.3.2. Prevent Resources from Moving after Recovery

Being a high-availability cluster, we should test failover of our new
resource before moving on. First, find the node on which the IP address
is running.

# pcs statusLast updated: Fri Sep 14 10:17:00 2012Last change: Fri Sep 14 10:15:48 2012 via cibadmin on pcmk-1
Stack: corosync
Current DC: pcmk-1 (1) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
1 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-1

Shut down Pacemaker and Corosync on that machine.

#pcs cluster stop pcmk-1Stopping Cluster...

Once Corosync is no longer running, go to the other node and check the
cluster status.

# pcs statusLast updated: Fri Sep 14 10:31:01 2012Last change: Fri Sep 14 10:15:48 2012 via cibadmin on pcmk-1
Stack: corosync
Current DC: pcmk-2 (2) - partition WITHOUT quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
1 Resources configured.

Online: [ pcmk-2 ]OFFLINE: [ pcmk-1 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Stopped

There are three things to notice about the cluster’s current state. The
first is that, as expected, pcmk-1 is now offline. However we can also
see that ClusterIP isn’t running anywhere!


5.3.1. Quorum and Two-Node Clusters

This is because the cluster no longer has quorum, as can be seen by the
text "partition WITHOUT quorum" in the status output. In order to reduce
the possibility of data corruption, Pacemaker’s default behavior is to
stop all resources if the cluster does not have quorum. A cluster is said
to have quorum when more than half the known or expected nodes are
online, or for the mathematically inclined, whenever the following
equation is true:

total_nodes < 2 * active_nodes

Therefore a two-node cluster only has quorum when both nodes are running,
which is no longer the case for our cluster. This would normally make the
creation of a two-node cluster pointless [14] , however it is possible to
control how Pacemaker behaves when quorum is lost. In particular, we can
tell the cluster to simply ignore quorum altogether.

# pcs property set no-quorum-policy=ignore# pcs propertydc-version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
cluster-infrastructure: corosync
stonith-enabled: falseno-quorum-policy: ignore

After a few moments, the cluster will start the IP address on the
remaining node. Note that the cluster still does not have quorum.

# pcs statusLast updated: Fri Sep 14 10:38:11 2012Last change: Fri Sep 14 10:37:53 2012 via cibadmin on pcmk-2
Stack: corosync
Current DC: pcmk-2 (2) - partition WITHOUT quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
1 Resources configured.

Online: [ pcmk-2 ]OFFLINE: [ pcmk-1 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-2

Now simulate node recovery by restarting the cluster stack on pcmk-1 and
check the cluster’s status. Note, if you get an authentication error with
the pcs cluster start pcmk-1 command, you must authenticate on the node
using the pcs cluster auth pcmk pcmk-1 pcmk-2 command discussed earlier.

# pcs cluster start pcmk-1Starting Cluster...# pcs statusLast updated: Fri Sep 14 10:42:56 2012Last change: Fri Sep 14 10:37:53 2012 via cibadmin on pcmk-2
Stack: corosync
Current DC: pcmk-2 (2) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
1 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-2


Note
----

In the dark days, the cluster may have moved the IP back to its original
location (pcmk-1). Usually this is no longer the case.


5.3.2. Prevent Resources from Moving after Recovery

In most circumstances, it is highly desirable to prevent healthy
resources from being moved around the cluster. Moving resources almost
always requires a period of downtime. For complex services like Oracle
databases, this period can be quite long. To address this, Pacemaker has
the concept of resource stickiness which controls how much a service
prefers to stay running where it is. You may like to think of it as the
"cost" of any downtime. By default, Pacemaker assumes there is zero cost
associated with moving resources and will do so to achieve "optimal" [15]
resource placement. We can specify a different stickiness for every
resource, but it is often sufficient to change the default.

# pcs resource rsc defaults resource-stickiness=100# pcs resource rsc defaultsresource-stickiness: 100


------------------------------------------------------------------------

[12] If the data is corrupt, there is little point in continuing to make
it available [13] A common node fencing mechanism. Used to ensure data
integrity by powering off "bad" nodes [14] Actually some would argue that
two-node clusters are always pointless, but that is an argument for
another time [15] It should be noted that Pacemaker’s definition of
optimal may not always agree with that of a human’s. The order in which
Pacemaker processes lists of resources and nodes creates implicit
preferences in situations where the administrator has not explicitly
specified them



Chapter 6. Apache - Adding More Services
========================================

6.1. Forward

6.2. Installation

6.3. Preparation

6.4. Enable the Apache status URL

6.5. Update the Configuration

6.6. Ensuring Resources Run on the Same Host

6.7. Controlling Resource Start/Stop Ordering

6.8. Specifying a Preferred Location

6.9. Manually Moving Resources Around the Cluster

      6.9.1. Giving Control Back to the Cluster


6.1. Forward
------------

Now that we have a basic but functional active/passive two-node cluster,
we’re ready to add some real services. We’re going to start with Apache
because its a feature of many clusters and relatively simple to
configure.


6.2. Installation
-----------------

Before continuing, we need to make sure Apache is installed on both
hosts. We also need the wget tool in order for the cluster to be able to
check the status of the Apache server.

# yum install -y httpd wget
Loaded plugins: langpacks, presto, refresh-packagekit
fedora/metalink                                               | 2.6 kB     00:00
updates/metalink                                              | 3.2 kB     00:00
updates-testing/metalink                                      |  41 kB     00:00
Resolving Dependencies
--> Running transaction check
---> Package httpd.x86_64 0:2.2.22-3.fc17 will be installed
--> Processing Dependency: httpd-tools = 2.2.22-3.fc17 for package: httpd-2.2.22-3.fc17.x86_64
--> Processing Dependency: apr-util-ldap for package: httpd-2.2.22-3.fc17.x86_64
--> Processing Dependency: libaprutil-1.so.0()(64bit) for package: httpd-2.2.22-3.fc17.x86_64
--> Processing Dependency: libapr-1.so.0()(64bit) for package: httpd-2.2.22-3.fc17.x86_64
--> Running transaction check
---> Package apr.x86_64 0:1.4.6-1.fc17 will be installed
---> Package apr-util.x86_64 0:1.4.1-2.fc17 will be installed
---> Package apr-util-ldap.x86_64 0:1.4.1-2.fc17 will be installed
---> Package httpd-tools.x86_64 0:2.2.22-3.fc17 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

=====================================================================================
 Package             Arch         Version                Repository             Size
=====================================================================================
Installing:
 httpd               x86_64       2.2.22-3.fc17          updates-testing       823 k
 wget                x86_64       1.13.4-2.fc17          fedora                495 k
Installing for dependencies:
 apr                 x86_64       1.4.6-1.fc17           fedora                 99 k
 apr-util            x86_64       1.4.1-2.fc17           fedora                 78 k
 apr-util-ldap       x86_64       1.4.1-2.fc17           fedora                 17 k
 httpd-tools         x86_64       2.2.22-3.fc17          updates-testing        74 k

Transaction Summary
=====================================================================================
Install  1 Package (+4 Dependent packages)

Total download size: 1.1 M
Installed size: 3.5 M
Downloading Packages:
(1/6): apr-1.4.6-1.fc17.x86_64.rpm                            |  99 kB     00:00
(2/6): apr-util-1.4.1-2.fc17.x86_64.rpm                       |  78 kB     00:00
(3/6): apr-util-ldap-1.4.1-2.fc17.x86_64.rpm                  |  17 kB     00:00
(4/6): httpd-2.2.22-3.fc17.x86_64.rpm                         | 823 kB     00:01
(5/6): httpd-tools-2.2.22-3.fc17.x86_64.rpm                   |  74 kB     00:00
(6/6): wget-1.13.4-2.fc17.x86_64.rpm                          | 495 kB     00:01
-------------------------------------------------------------------------------------
Total                                                238 kB/s | 1.1 MB     00:04
Running Transaction Check
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : apr-1.4.6-1.fc17.x86_64                                           1/6
  Installing : apr-util-1.4.1-2.fc17.x86_64                                      2/6
  Installing : apr-util-ldap-1.4.1-2.fc17.x86_64                                 3/6
  Installing : httpd-tools-2.2.22-3.fc17.x86_64                                  4/6
  Installing : httpd-2.2.22-3.fc17.x86_64                                        5/6
  Installing : wget-1.13.4-2.fc17.x86_64                                         6/6
  Verifying  : apr-util-ldap-1.4.1-2.fc17.x86_64                                 1/6
  Verifying  : httpd-tools-2.2.22-3.fc17.x86_64                                  2/6
  Verifying  : apr-util-1.4.1-2.fc17.x86_64                                      3/6
  Verifying  : apr-1.4.6-1.fc17.x86_64                                           4/6
  Verifying  : httpd-2.2.22-3.fc17.x86_64                                        5/6
  Verifying  : wget-1.13.4-2.fc17.x86_64                                         6/6

Installed:
  httpd.x86_64 0:2.2.22-3.fc17              wget.x86_64 0:1.13.4-2.fc17

Dependency Installed:
  apr.x86_64 0:1.4.6-1.fc17                 apr-util.x86_64 0:1.4.1-2.fc17
  apr-util-ldap.x86_64 0:1.4.1-2.fc17       httpd-tools.x86_64 0:2.2.22-3.fc17

Complete!


6.3. Preparation
----------------

First we need to create a page for Apache to serve up. On Fedora the
default Apache docroot is /var/www/html, so we’ll create an index file
there.

# cat <<-END >/var/www/html/index.html <html> <body>My Test Site - pcmk-1</body> </html>END

For the moment, we will simplify things by serving up only a static site
and manually sync the data between the two nodes. So run the command
again on pcmk-2.

[root@pcmk-2 ~]# cat <<-END >/var/www/html/index.html <html> <body>My Test Site - pcmk-2</body>
 </html>
 END


6.4. Enable the Apache status URL
---------------------------------

In order to monitor the health of your Apache instance, and recover it if
it fails, the resource agent used by Pacemaker assumes the server-status
URL is available. Look for the following in /etc/httpd/conf/httpd.conf
and make sure it is not disabled or commented out:

<Location /server-status>
   SetHandler server-status
   Order deny,allow
   Deny from all
   Allow from 127.0.0.1
</Location>


6.5. Update the Configuration
-----------------------------

At this point, Apache is ready to go, all that needs to be done is to add
it to the cluster. Lets call the resource WebSite. We need to use an OCF
script called apache in the heartbeat namespace [16] , the only required
parameter is the path to the main Apache configuration file and we’ll
tell the cluster to check once a minute that apache is still running.

# pcs resource create WebSite ocf:heartbeat:apache  \      configfile=/etc/httpd/conf/httpd.conf \
      statusurl="http://localhost/server-status" op monitor interval=1min

By default, the operation timeout for all resource’s start, stop, and
monitor operations is 20 seconds. In many cases this timeout period is
less than the advised timeout period. For the purposes of this tutorial,
we will adjust the global operation timeout default to 240 seconds.

# pcs resource op defaults timeout=240s# pcs resource op defaultstimeout: 240s

After a short delay, we should see the cluster start apache

# pcs statusLast updated: Fri Sep 14 10:51:27 2012Last change: Fri Sep 14 10:50:46 2012 via crm_attribute on pcmk-1
Stack: corosync
Current DC: pcmk-2 (2) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
2 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-2
 WebSite        (ocf::heartbeat:apache):        Started pcmk-1

Wait a moment, the WebSite resource isn’t running on the same host as our
IP address!


Note
----

If, in the pcs status output, you see the WebSite resource has failed to
start, then you’ve likely not enabled the status URL correctly. You can
check if this is the problem by running:

wget http://127.0.0.1/server-status

If you see Connection refused in the output, then this is indeed the
problem. Check to ensure that Allow from 127.0.0.1 is present for the
<Location /server-status> block.


6.6. Ensuring Resources Run on the Same Host
--------------------------------------------

To reduce the load on any one machine, Pacemaker will generally try to
spread the configured resources across the cluster nodes. However we can
tell the cluster that two resources are related and need to run on the
same host (or not at all). Here we instruct the cluster that WebSite can
only run on the host that ClusterIP is active on. To achieve this we use
a colocation constraint that indicates it is mandatory for WebSite to run
on the same node as ClusterIP. The "mandatory" part of the colocation
constraint is indicated by using a score of INFINITY. The INFINITY score
also means that if ClusterIP is not active anywhere, WebSite will not be
permitted to run.


Note
----

If ClusterIP is not active anywhere, WebSite will not be permitted to run
anywhere.


Important
---------

Colocation constraints are "directional", in that they imply certain
things about the order in which the two resources will have a location
chosen. In this case we’re saying WebSite needs to be placed on the same
machine as ClusterIP, this implies that we must know the location of
ClusterIP before choosing a location for WebSite.

# pcs constraint colocation add WebSite ClusterIP INFINITY# pcs constraintLocation Constraints:
Ordering Constraints:
Colocation Constraints:
  WebSite with ClusterIP# pcs statusLast updated: Fri Sep 14 11:00:44 2012Last change: Fri Sep 14 11:00:25 2012 via cibadmin on pcmk-1
Stack: corosync
Current DC: pcmk-2 (2) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
2 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-2
 WebSite        (ocf::heartbeat:apache):        Started pcmk-2


6.7. Controlling Resource Start/Stop Ordering
---------------------------------------------

When Apache starts, it binds to the available IP addresses. It doesn’t
know about any addresses we add afterwards, so not only do they need to
run on the same node, but we need to make sure ClusterIP is already
active before we start WebSite. We do this by adding an ordering
constraint. By default all order constraints are mandatory constraints
unless otherwise configured. This means that the recovery of ClusterIP
will also trigger the recovery of WebSite.

# pcs constraint order ClusterIP then WebSiteAdding ClusterIP WebSite (kind: Mandatory) (Options: first-action=start then-action=start)# pcs constraintLocation Constraints:
Ordering Constraints:
  start ClusterIP then start WebSite
Colocation Constraints:
  WebSite with ClusterIP


6.8. Specifying a Preferred Location
------------------------------------

Pacemaker does not rely on any sort of hardware symmetry between nodes,
so it may well be that one machine is more powerful than the other. In
such cases it makes sense to host the resources there if it is available.
To do this we create a location constraint. In the location constraint
below, we are saying the WebSite resource prefers the node pcmk-1 with a
score of 50. The score here indicates how badly we’d like the resource to
run somewhere.

# pcs constraint location WebSite prefers pcmk-1=50# pcs constraintLocation Constraints:
  Resource: WebSite
    Enabled on: pcmk-1 (score:50)Ordering Constraints:
  start ClusterIP then start WebSite
Colocation Constraints:
  WebSite with ClusterIP# pcs statusLast updated: Fri Sep 14 11:06:37 2012Last change: Fri Sep 14 11:06:26 2012 via cibadmin on pcmk-1
Stack: corosync
Current DC: pcmk-2 (2) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
2 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-2
 WebSite        (ocf::heartbeat:apache):        Started pcmk-2

Wait a minute, the resources are still on pcmk-2! Even though we now
prefer pcmk-1 over pcmk-2, that preference is (intentionally) less than
the resource stickiness (how much we preferred not to have unnecessary
downtime). To see the current placement scores, you can use a tool called
crm_simulate

# crm_simulate -sLCurrent cluster status:
Online: [ pcmk-1 pcmk-2 ]
 ClusterIP      (ocf:heartbeat:IPaddr2):        Started pcmk-2
 WebSite        (ocf:heartbeat:apache): Started pcmk-2

Allocation scores:
native_color: ClusterIP allocation score on pcmk-1: 50
native_color: ClusterIP allocation score on pcmk-2: 200
native_color: WebSite allocation score on pcmk-1: -INFINITY
native_color: WebSite allocation score on pcmk-2: 100

Transition Summary:


6.9. Manually Moving Resources Around the Cluster
-------------------------------------------------

6.9.1. Giving Control Back to the Cluster

There are always times when an administrator needs to override the
cluster and force resources to move to a specific location. By updating
our previous location constraint with a score of INFINITY, WebSite will
be forced to move to pcmk-1.

# pcs constraint location WebSite prefers pcmk-1=INFINITY# pcs constraint allLocation Constraints:
  Resource: WebSite
    Enabled on: pcmk-1 (score:INFINITY) (id:location-WebSite-pcmk-1-INFINITY)Ordering Constraints:
  start ClusterIP then start WebSite (Mandatory) (id:order-ClusterIP-WebSite-mandatory)Colocation Constraints:
  WebSite with ClusterIP (INFINITY) (id:colocation-WebSite-ClusterIP-INFINITY)# pcs statusLast updated: Fri Sep 14 11:16:26 2012Last change: Fri Sep 14 11:16:18 2012 via cibadmin on pcmk-1
Stack: corosync
Current DC: pcmk-2 (2) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
2 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-1
 WebSite        (ocf::heartbeat:apache):        Started pcmk-1


6.9.1. Giving Control Back to the Cluster

Once we’ve finished whatever activity that required us to move the
resources to pcmk-1, in our case nothing, we can then allow the cluster
to resume normal operation with the unmove command. Since we previously
configured a default stickiness, the resources will remain on pcmk-1.

# pcs constraint allLocation Constraints:
  Resource: WebSite
    Enabled on: pcmk-1 (score:INFINITY) (id:location-WebSite-pcmk-1-INFINITY)Ordering Constraints:
  start ClusterIP then start WebSite (Mandatory) (id:order-ClusterIP-WebSite-mandatory)Colocation Constraints:
  WebSite with ClusterIP (INFINITY) (id:colocation-WebSite-ClusterIP-INFINITY)# pcs constraint rm location-WebSite-pcmk-1-INFINITY# pcs constraintLocation Constraints:
Ordering Constraints:
  start ClusterIP then start WebSite
Colocation Constraints:
  WebSite with ClusterIP

Note that the constraint is now gone. If we check the cluster status, we
can also see that as expected the resources are still active on pcmk-1.

# pcs statusLast updated: Fri Sep 14 11:57:12 2012Last change: Fri Sep 14 11:57:03 2012 via cibadmin on pcmk-1
Stack: corosync
Current DC: pcmk-2 (2) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
2 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-1
 WebSite        (ocf::heartbeat:apache):        Started pcmk-1


------------------------------------------------------------------------

[16] Compare the key used here ocf:heartbeat:apache with the one we used
earlier for the IP address: ocf:heartbeat:IPaddr2



Chapter 7. Replicated Storage with DRBD
=======================================

7.1. Background

7.2. Install the DRBD Packages

7.3. Configure DRBD

      7.3.1. Create A Partition for DRBD

      7.3.2. Write the DRBD Config

      7.3.3. Initialize and Load DRBD

      7.3.4. Populate DRBD with Data

7.4. Configure the Cluster for DRBD

      7.4.1. Testing Migration


7.1. Background
---------------

Even if you’re serving up static websites, having to manually synchronize
the contents of that website to all the machines in the cluster is not
ideal. For dynamic websites, such as a wiki, it’s not even an option. Not
everyone care afford network-attached storage but somehow the data needs
to be kept in sync. Enter DRBD which can be thought of as network based
RAID-1. See http://www.drbd.org/ for more details.


7.2. Install the DRBD Packages
------------------------------

Since its inclusion in the upstream 2.6.33 kernel, everything needed to
use DRBD has shiped with Fedora since version 13. All you need to do is
install it:

# yum install -y drbd-pacemaker drbd-udev
Loaded plugins: langpacks, presto, refresh-packagekit
Resolving Dependencies
--> Running transaction check
---> Package drbd-pacemaker.x86_64 0:8.3.11-5.fc17 will be installed
--> Processing Dependency: drbd-utils = 8.3.11-5.fc17 for package: drbd-pacemaker-8.3.11-5.fc17.x86_64
---> Package drbd-udev.x86_64 0:8.3.11-5.fc17 will be installed
--> Running transaction check
---> Package drbd-utils.x86_64 0:8.3.11-5.fc17 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

======================================================================================
 Package              Arch         Version                Repository             Size
======================================================================================
Installing:
 drbd-pacemaker       x86_64       8.3.11-5.fc17          updates-testing        22 k
 drbd-udev            x86_64       8.3.11-5.fc17          updates-testing       6.4 k
Installing for dependencies:
 drbd-utils           x86_64       8.3.11-5.fc17          updates-testing       183 k

Transaction Summary
======================================================================================
Install  2 Packages (+1 Dependent package)

Total download size: 212 k
Installed size: 473 k
Downloading Packages:
(1/3): drbd-pacemaker-8.3.11-5.fc17.x86_64.rpm                 |  22 kB     00:00
(2/3): drbd-udev-8.3.11-5.fc17.x86_64.rpm                      | 6.4 kB     00:00
(3/3): drbd-utils-8.3.11-5.fc17.x86_64.rpm                     | 183 kB     00:00
--------------------------------------------------------------------------------------
Total                                                 293 kB/s | 212 kB     00:00
Running Transaction Check
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : drbd-utils-8.3.11-5.fc17.x86_64                                    1/3
  Installing : drbd-pacemaker-8.3.11-5.fc17.x86_64                                2/3
  Installing : drbd-udev-8.3.11-5.fc17.x86_64                                     3/3
  Verifying  : drbd-pacemaker-8.3.11-5.fc17.x86_64                                1/3
  Verifying  : drbd-udev-8.3.11-5.fc17.x86_64                                     2/3
  Verifying  : drbd-utils-8.3.11-5.fc17.x86_64                                    3/3

Installed:
  drbd-pacemaker.x86_64 0:8.3.11-5.fc17        drbd-udev.x86_64 0:8.3.11-5.fc17

Dependency Installed:
  drbd-utils.x86_64 0:8.3.11-5.fc17

Complete!


7.3. Configure DRBD
-------------------

7.3.1. Create A Partition for DRBD

7.3.2. Write the DRBD Config

7.3.3. Initialize and Load DRBD

7.3.4. Populate DRBD with Data

Before we configure DRBD, we need to set aside some disk for it to use.


7.3.1. Create A Partition for DRBD

If you have more than 1Gb free, feel free to use it. For this guide
however, 1Gb is plenty of space for a single html file and sufficient for
later holding the GFS2 metadata.

# vgdisplay | grep -e Name - e Free  VG Name               vg_pcmk1
  Free  PE / Size       31 / 992.00 MiB# lvs  LV        VG          Attr     LSize   Pool Origin Data%  Move Log Copy%  Convert
  lv_root   vg_pcmk1 -wi-ao--   8.56g
  lv_swap   vg_pcmk1 -wi-ao-- 960.00m# lvcreate -n drbd-demo -L 1G vg_pcmk1Logical volume "drbd-demo" created# lvs  LV        VG          Attr     LSize   Pool Origin Data%  Move Log Copy%  Convert
  drbd-demo vg_pcmk1 -wi-a--- 1.00G
  lv_root   vg_pcmk1 -wi-ao--   8.56g
  lv_swap   vg_pcmk1 -wi-ao-- 960.00m

Repeat this on the second node, be sure to use the same size partition.

# ssh pcmk-2 -- lvsLV   VG    Attr  LSize  Origin Snap% Move Log Copy% Convert
  lv_root   vg_pcmk1 -wi-ao--   8.56g
  lv_swap   vg_pcmk1 -wi-ao-- 960.00m# ssh pcmk-2 -- lvcreate -n drbd-demo -L 1G vg_pcmk1Logical volume "drbd-demo" created# ssh pcmk-2 -- lvsLV    VG    Attr  LSize  Origin Snap% Move Log Copy% Convert
  drbd-demo vg_pcmk1 -wi-a--- 1.00G
  lv_root   vg_pcmk1 -wi-ao--   8.56g
  lv_swap   vg_pcmk1 -wi-ao-- 960.00m


7.3.2. Write the DRBD Config

There is no series of commands for building a DRBD configuration, so
simply copy the configuration below to /etc/drbd.conf Detailed
information on the directives used in this configuration (and other
alternatives) is available from
http://www.drbd.org/users-guide/ch-configure.html


Warning
-------

Be sure to use the names and addresses of your nodes if they differ from
the ones used in this guide.

global {
 usage-count yes;
}
common {
 protocol C;
}
resource wwwdata {
 meta-disk internal;
 device  /dev/drbd1;
 syncer {
  verify-alg sha1;
 }
 net {
  allow-two-primaries;
 }
 on pcmk-1 {
  disk   /dev/vg_pcmk1/drbd-demo;
  address  192.168.122.101:7789;
 }
 on pcmk-2 {
  disk   /dev/vg_pcmk1/drbd-demo;
  address  192.168.122.102:7789;
 }
}


Note
----

TODO: Explain the reason for the allow-two-primaries option


7.3.3. Initialize and Load DRBD

With the configuration in place, we can now perform the DRBD
initialization

# drbdadm create-md wwwdataWriting meta data...
initializing activity log
NOT initialized bitmap
New drbd meta data block successfully created.
success

Now load the DRBD kernel module and confirm that everything is sane

# modprobe drbd# drbdadm up wwwdata# cat /proc/drbdversion: 8.3.11 (api:88/proto:86-96)srcversion: 0D2B62DEDB020A425130935

 1: cs:Connected ro:Secondary/Secondary ds:Inconsistent/Inconsistent C r-----
    ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:1015740

Repeat on the second node

# ssh pcmk-2 -- drbdadm --force create-md wwwdataWriting meta data...
initializing activity log
NOT initialized bitmap
New drbd meta data block successfully created.
success# ssh pcmk-2 -- modprobe drbdWARNING: Deprecated config file /etc/modprobe.conf, all config files belong into /etc/modprobe.d/.# ssh pcmk-2 -- drbdadm up wwwdata# ssh pcmk-2 -- cat /proc/drbdversion: 8.3.11 (api:88/proto:86-96)srcversion: 0D2B62DEDB020A425130935

 1: cs:Connected ro:Secondary/Secondary ds:Inconsistent/Inconsistent C r-----
    ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:1015740

Now we need to tell DRBD which set of data to use. Since both sides
contain garbage, we can run the following on pcmk-1:

# drbdadm -- --overwrite-data-of-peer primary wwwdata# cat /proc/drbdversion: 8.3.11 (api:88/proto:86-96)srcversion: 0D2B62DEDB020A425130935

 1: cs:SyncSource ro:Primary/Secondary ds:UpToDate/Inconsistent C r-----
    ns:8064 nr:0 dw:0 dr:8728 al:0 bm:0 lo:0 pe:1 ua:0 ap:0 ep:1 wo:f oos:1007804
        [>....................] sync'ed:  0.9% (1007804/1015740)K        finish: 0:12:35 speed: 1,320 (1,320) K/sec

After a while, the sync should finish and you’ll see:

# cat /proc/drbdversion: 8.3.11 (api:88/proto:86-96)srcversion: 0D2B62DEDB020A425130935

 1: cs:Connected ro:Primary/Secondary ds:UpToDate/UpToDate C r-----
    ns:1015740 nr:0 dw:0 dr:1016404 al:0 bm:62 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:0

pcmk-1 is now in the Primary state which allows it to be written to.
Which means it’s a good point at which to create a filesystem and
populate it with some data to serve up via our WebSite resource.


7.3.4. Populate DRBD with Data

# mkfs.ext4 /dev/drbd1mke2fs 1.42 (29-Nov-2011)Filesystem label=OS type: Linux
Block size=4096 (log=2)Fragment size=4096 (log=2)Stride=0 blocks, Stripe width=0 blocks
63488 inodes, 253935 blocks
12696 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=260046848
8 block groups32768 blocks per group, 32768 fragments per group
7936 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376

Allocating group tables: doneWriting inode tables: doneCreating journal (4096 blocks): doneWriting superblocks and filesystem accounting information: done

Now mount the newly created filesystem so we can create our index file

# mount /dev/drbd1 /mnt/# cat <<-END >/mnt/index.html <html>  <body>My Test Site - drbd</body> </html>END# umount /dev/drbd1


7.4. Configure the Cluster for DRBD
-----------------------------------

7.4.1. Testing Migration

One handy feature pcs has is the ability to queue up several changes into
a file and commit those changes atomically. To do this, start by
populating the file with the current raw xml config from the cib. This
can be done using the following command.

# pcs cluster cib drbd_cfg

Now using the pcs -f option, make changes to the configuration saved in
the drbd_cfg file. These changes will not be seen by the cluster until
the drbd_cfg file is pushed into the live cluster’s cib later on.

# pcs -f drbd_cfg resource create WebData ocf:linbit:drbd \         drbd_resource=wwwdata op monitor interval=60s# pcs -f drbd_cfg resource master WebDataClone WebData \         master-max=1 master-node-max=1 clone-max=2 clone-node-max=1 \
         notify=true# pcs -f drbd_cfg resource show ClusterIP      (ocf::heartbeat:IPaddr2) Started
 WebSite        (ocf::heartbeat:apache) Started
 Master/Slave Set: WebDataClone [WebData]
     Stopped: [ WebData:0 WebData:1 ]

After you are satisfied with all the changes, you can commit all the
changes at once by pushing the drbd_cfg file into the live cib.

# pcs cluster push cib drbd_cfgCIB updated## pcs statusLast updated: Fri Sep 14 12:19:49 2012Last change: Fri Sep 14 12:19:13 2012 via cibadmin on pcmk-1
Stack: corosync
Current DC: pcmk-2 (2) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
4 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-1
 WebSite        (ocf::heartbeat:apache):        Started pcmk-1
 Master/Slave Set: WebDataClone [WebData]
     Masters: [ pcmk-1 ]     Slaves: [ pcmk-2 ]


Note
----

TODO: Include details on adding a second DRBD resource Now that DRBD is
functioning we can configure a Filesystem resource to use it. In addition
to the filesystem’s definition, we also need to tell the cluster where it
can be located (only on the DRBD Primary) and when it is allowed to start
(after the Primary was promoted). Once again we will queue up our changes
to a file and then push the new configuration to the cluster as the final
step.

# pcs cluster cib fs_cfg# pcs -f fs_cfg resource create WebFS ocf:heartbeat:Filesystem \         device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" \
         fstype="ext4"# pcs -f fs_cfg constraint colocation add WebFS WebDataClone INFINITY with-rsc-role=Master# pcs -f fs_cfg constraint order promote WebDataClone then start WebFSAdding WebDataClone WebFS (kind: Mandatory) (Options: first-action=promote then-action=start)

We also need to tell the cluster that Apache needs to run on the same
machine as the filesystem and that it must be active before Apache can
start.

# pcs -f fs_cfg constraint colocation add WebSite WebFS INFINITY# pcs -f fs_cfg constraint order WebFS then WebSite

Now review the updated configuration.

# pcs -f fs_cfg constraintLocation Constraints:
Ordering Constraints:
  start ClusterIP then start WebSite
  WebFS then WebSite
  promote WebDataClone then start WebFS
Colocation Constraints:
  WebSite with ClusterIP
  WebFS with WebDataClone (with-rsc-role:Master)  WebSite with WebFS## pcs -f fs_cfg resource show ClusterIP      (ocf::heartbeat:IPaddr2) Started
 WebSite        (ocf::heartbeat:apache) Started
 Master/Slave Set: WebDataClone [WebData]
     Masters: [ pcmk-1 ]     Slaves: [ pcmk-2 ] WebFS  (ocf::heartbeat:Filesystem) Stopped

After reviewing the new configuration, we again upload it and watch the
cluster put it into effect.

# pcs cluster push cib fs_cfgCIB updated# pcs status Last updated: Fri Aug 10 12:47:01 2012

 Last change: Fri Aug 10 12:46:55 2012 via cibadmin on pcmk-1
 Stack: corosync
 Current DC: pcmk-1 (1) - partition with quorum
 Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
 2 Nodes configured, unknown expected votes
 5 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-1
 WebSite        (ocf::heartbeat:apache):        Started pcmk-1
 Master/Slave Set: WebDataClone [WebData]
     Masters: [ pcmk-1 ]     Slaves: [ pcmk-2 ] WebFS  (ocf::heartbeat:Filesystem):    Started pcmk-1


7.4.1. Testing Migration

We could shut down the active node again, but another way to safely
simulate recovery is to put the node into what is called "standby mode".
Nodes in this state tell the cluster that they are not allowed to run
resources. Any resources found active there will be moved elsewhere. This
feature can be particularly useful when updating the resources' packages.
Put the local node into standby mode and observe the cluster move all the
resources to the other node. Note also that the node’s status will change
to indicate that it can no longer host resources.

# pcs cluster standby pcmk-1# pcs statusLast updated: Fri Sep 14 12:41:12 2012Last change: Fri Sep 14 12:41:08 2012 via crm_attribute on pcmk-1
Stack: corosync
Current DC: pcmk-1 (1) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
5 Resources configured.

Node pcmk-1 (1): standby
Online: [ pcmk-2 ]
Full list of resources:

ClusterIP       (ocf::heartbeat:IPaddr2):       Started pcmk-2
WebSite (ocf::heartbeat:apache):        Started pcmk-2
 Master/Slave Set: WebDataClone [WebData]
     Masters: [ pcmk-2 ]     Stopped: [ WebData:1 ]WebFS   (ocf::heartbeat:Filesystem):    Started pcmk-2

Once we’ve done everything we needed to on pcmk-1 (in this case nothing,
we just wanted to see the resources move), we can allow the node to be a
full cluster member again.

# pcs cluster unstandby pcmk-1# pcs statusLast updated: Fri Sep 14 12:43:02 2012Last change: Fri Sep 14 12:42:57 2012 via crm_attribute on pcmk-1
Stack: corosync
Current DC: pcmk-1 (1) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
5 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-2
 WebSite        (ocf::heartbeat:apache):        Started pcmk-2
 Master/Slave Set: WebDataClone [WebData]
     Masters: [ pcmk-2 ]     Slaves: [ pcmk-1 ] WebFS  (ocf::heartbeat:Filesystem):    Started pcmk-2

Notice that our resource stickiness settings prevent the services from
migrating back to pcmk-1.



Chapter 8. Conversion to Active/Active
======================================

8.1. Requirements

      8.1.1. Installing the required Software

8.2. Create a GFS2 Filesystem

      8.2.1. Preparation

      8.2.2. Create and Populate an GFS2 Partition

8.3. Reconfigure the Cluster for GFS2

8.4. Reconfigure Pacemaker for Active/Active

      8.4.1. Testing Recovery


8.1. Requirements
-----------------

8.1.1. Installing the required Software

The primary requirement for an Active/Active cluster is that the data
required for your services is available, simultaneously, on both
machines. Pacemaker makes no requirement on how this is achieved, you
could use a SAN if you had one available, however since DRBD supports
multiple Primaries, we can also use that. The only hitch is that we need
to use a cluster-aware filesystem. The one we used earlier with DRBD,
ext4, is not one of those. Both OCFS2 and GFS2 are supported, however
here we will use GFS2 which comes with Fedora 17.


8.1.1. Installing the required Software

# yum install -y gfs2-utils dlm kernel-modules-extraLoaded plugins: langpacks, presto, refresh-packagekit
Resolving Dependencies
--> Running transaction check
---> Package dlm.x86_64 0:3.99.4-1.fc17 will be installed
---> Package gfs2-utils.x86_64 0:3.1.4-3.fc17 will be installed
---> Package kernel-modules-extra.x86_64 0:3.4.4-3.fc17 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package                Arch       Version          Repository           Size================================================================================
Installing:
 dlm                    x86_64     3.99.4-1.fc17    updates              83 k
 gfs2-utils             x86_64     3.1.4-3.fc17     fedora              214 k
 kernel-modules-extra   x86_64     3.4.4-3.fc17     updates             1.7 M

Transaction Summary
================================================================================Install  3 Packages

Total download size: 1.9 M
Installed size: 7.7 M
Downloading Packages:(1/3): dlm-3.99.4-1.fc17.x86_64.rpm                         |  83 kB     00:00(2/3): gfs2-utils-3.1.4-3.fc17.x86_64.rpm                   | 214 kB     00:00(3/3): kernel-modules-extra-3.4.4-3.fc17.x86_64.rpm         | 1.7 MB     00:01
 -------------------------------------------------------------------------------
Total                                              615 kB/s | 1.9 MB     00:03
Running Transaction Check
Running Transaction TestTransaction Test Succeeded
Running Transaction
  Installing : kernel-modules-extra-3.4.4-3.fc17.x86_64                 1/3
  Installing : gfs2-utils-3.1.4-3.fc17.x86_64                           2/3
  Installing : dlm-3.99.4-1.fc17.x86_64                                 3/3
  Verifying  : dlm-3.99.4-1.fc17.x86_64                                 1/3
  Verifying  : gfs2-utils-3.1.4-3.fc17.x86_64                           2/3
  Verifying  : kernel-modules-extra-3.4.4-3.fc17.x86_64                 3/3

Installed:
  dlm.x86_64 0:3.99.4-1.fc17
  gfs2-utils.x86_64 0:3.1.4-3.fc17
  kernel-modules-extra.x86_64 0:3.4.4-3.fc17
Complete!


8.2. Create a GFS2 Filesystem
-----------------------------

8.2.1. Preparation

8.2.2. Create and Populate an GFS2 Partition


8.2.1. Preparation

Before we do anything to the existing partition, we need to make sure it
is unmounted. We do this by telling the cluster to stop the WebFS
resource. This will ensure that other resources (in our case, Apache)
using WebFS are not only stopped, but stopped in the correct order.

# pcs resource stop WebFS# pcs resource ClusterIP      (ocf::heartbeat:IPaddr2) Started
 WebSite        (ocf::heartbeat:apache) Stopped
 Master/Slave Set: WebDataClone [WebData]
     Masters: [ pcmk-2 ]     Slaves: [ pcmk-1 ] WebFS  (ocf::heartbeat:Filesystem) Stopped


Note
----

Note that both Apache and WebFS have been stopped.


8.2.2. Create and Populate an GFS2 Partition

Now that the cluster stack and integration pieces are running smoothly,
we can create an GFS2 partition.


Warning
-------

This will erase all previous content stored on the DRBD device. Ensure
you have a copy of any important data. We need to specify a number of
additional parameters when creating a GFS2 partition. First we must use
the -p option to specify that we want to use the the Kernel’s DLM. Next
we use -j to indicate that it should reserve enough space for two
journals (one per node accessing the filesystem). Lastly, we use -t to
specify the lock table name. The format for this field is
clustername:fsname. For the fsname, we need to use the same value as
specified in corosync.conf for cluster_name. If you setup corosync with
the same cluster name we used in this tutorial, cluster name will be
mycluster. If you are unsure what your cluster name is, open up
/etc/corosync/corosync.conf, or execute the command pcs cluster corosync
pcmk-1 to view the corosync config. The cluster name will be in the totem
block.


Important
---------

We must run the next command on whichever node last had /dev/drbd
mounted. Otherwise you will receive the message:

/dev/drbd1: Read-only file system

# ssh pcmk-2 -- mkfs.gfs2 -p lock_dlm -j 2 -t mycluster:web /dev/drbd1This will destroy any data on /dev/drbd1.
It appears to contain: Linux rev 1.0 ext4 filesystem data, UUID=dc45fff3-c47a-4db2-96f7-a8049a323fe4 (extents) (large files) (huge files)Are you sure you want to proceed? [y/n]y
Device:                    /dev/drbd1
Blocksize:                 4096
Device Size                0.97 GB (253935 blocks)Filesystem Size:           0.97 GB (253932 blocks)Journals:                  2
Resource Groups:           4
Locking Protocol:          "lock_dlm"Lock Table:                "mycluster"UUID:                      ed293a02-9eee-3fa3-ed1c-435ef1fd0116

# pcs cluster cib dlm_cfg# pcs -f dlm_cfg resource create dlm ocf:pacemaker:controld op monitor interval=60s# pcs -f dlm_cfg resource clone dlm clone-max=2 clone-node-max=1# pcs -f dlm_cfg resource show ClusterIP      (ocf::heartbeat:IPaddr2) Started
 WebSite        (ocf::heartbeat:apache) Stopped
 Master/Slave Set: WebDataClone [WebData]
     Masters: [ pcmk-2 ]     Slaves: [ pcmk-1 ] WebFS  (ocf::heartbeat:Filesystem) Stopped
 Clone Set: dlm-clone [dlm]
     Stopped: [ dlm:0 dlm:1 ]# pcs cluster push cib dlm_cfgCIB updated# pcs statusLast updated: Fri Sep 14 12:54:50 2012Last change: Fri Sep 14 12:54:43 2012 via cibadmin on pcmk-1
Stack: corosync
Current DC: pcmk-1 (1) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
7 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 ClusterIP      (ocf::heartbeat:IPaddr2):       Started pcmk-2
 WebSite        (ocf::heartbeat:apache):        Stopped
 Master/Slave Set: WebDataClone [WebData]
     Masters: [ pcmk-2 ]     Slaves: [ pcmk-1 ] WebFS  (ocf::heartbeat:Filesystem):    Stopped
 Clone Set: dlm-clone [dlm]
     Started: [ pcmk-1 pcmk-2 ]

Then (re)populate the new filesystem with data (web pages). For now we’ll
create another variation on our home page.

# mount /dev/drbd1 /mnt/# cat <<-END >/mnt/index.html<html><body>My Test Site - GFS2</body></html>END# umount /dev/drbd1# drbdadm verify wwwdata#


8.3. Reconfigure the Cluster for GFS2
-------------------------------------

With the WebFS resource stopped, lets update the configuration.

# pcs resource show WebFSResource: WebFS
  device: /dev/drbd/by-res/wwwdata
  directory: /var/www/html
  fstype: ext4
  target-role: Stopped

The fstype option needs to be updated to gfs2 instead of ext4.

# pcs resource update WebFS fstype=gfs2# pcs resource show WebFSResource: WebFS
  device: /dev/drbd/by-res/wwwdata
  directory: /var/www/html
  fstype: gfs2
  target-role: Stopped
CIB updated


8.4. Reconfigure Pacemaker for Active/Active
--------------------------------------------

8.4.1. Testing Recovery

Almost everything is in place. Recent versions of DRBD are capable of
operating in Primary/Primary mode and the filesystem we’re using is
cluster aware. All we need to do now is reconfigure the cluster to take
advantage of this. This will involve a number of changes, so we’ll want
work with a local cib file.

# pcs cluster cib active_cfg

There’s no point making the services active on both locations if we can’t
reach them, so lets first clone the IP address. Cloned IPaddr2 resources
use an iptables rule to ensure that each request only gets processed by
one of the two clone instances. The additional meta options tell the
cluster how many instances of the clone we want (one "request bucket" for
each node) and that if all other nodes fail, then the remaining node
should hold all of them. Otherwise the requests would be simply
discarded.

# pcs -f active_cfg resource clone ClusterIP \     globally-unique=true clone-max=2 clone-node-max=2

Notice when the ClusterIP becomes a clone, the constraints referencing
ClusterIP now reference the clone. This is done automatically by pcs.

# pcs -f active_cfg constraintLocation Constraints:
Ordering Constraints:
  start ClusterIP-clone then start WebSite
  WebFS then WebSite
  promote WebDataClone then start WebFS
Colocation Constraints:
  WebSite with ClusterIP-clone
  WebFS with WebDataClone (with-rsc-role:Master)  WebSite with WebFS

Now we must tell the ClusterIP how to decide which requests are processed
by which hosts. To do this we must specify the clusterip_hash parameter.

# pcs -f active_cfg resource update ClusterIP clusterip_hash=sourceip

Next we need to convert the filesystem and Apache resources into clones.
Notice how pcs automatically updates the relevant constraints again.

# pcs -f active_cfg resource clone WebFS# pcs -f active_cfg resource clone WebSite# pcs -f active_cfg constraintLocation Constraints:
Ordering Constraints:
  start ClusterIP-clone then start WebSite-clone
  WebFS-clone then WebSite-clone
  promote WebDataClone then start WebFS-clone
Colocation Constraints:
  WebSite-clone with ClusterIP-clone
  WebFS-clone with WebDataClone (with-rsc-role:Master)  WebSite-clone with WebFS-clone

The last step is to tell the cluster that it is now allowed to promote
both instances to be Primary (aka. Master).

# pcs -f active_cfg resource update WebDataClone master-max=2

Review the configuration before uploading it to the cluster, quitting the
shell and watching the cluster’s response

# pcs cluster push cib active_cfg# pcs resource start WebFS

After all the processes are started the status should look similar to
this.

# pcs resource Master/Slave Set: WebDataClone [WebData]
     Masters: [ pcmk-2 pcmk-1 ] Clone Set: dlm-clone [dlm]
     Started: [ pcmk-2 pcmk-1 ] Clone Set: ClusterIP-clone [ClusterIP] (unique)     ClusterIP:0        (ocf::heartbeat:IPaddr2) Started
     ClusterIP:1        (ocf::heartbeat:IPaddr2) Started
 Clone Set: WebFS-clone [WebFS]
     Started: [ pcmk-1 pcmk-2 ] Clone Set: WebSite-clone [WebSite]
     Started: [ pcmk-1 pcmk-2 ]


8.4.1. Testing Recovery


Note
----

TODO: Put one node into standby to demonstrate failover



Chapter 9. Configure STONITH
============================

9.1. What Is STONITH

9.2. What STONITH Device Should You Use

9.3. Configuring STONITH

9.4. Example


9.1. What Is STONITH
--------------------

STONITH is an acronym for Shoot-The-Other-Node-In-The-Head and it
protects your data from being corrupted by rogue nodes or concurrent
access. Just because a node is unresponsive, this doesn’t mean it isn’t
accessing your data. The only way to be 100% sure that your data is safe,
is to use STONITH so we can be certain that the node is truly offline,
before allowing the data to be accessed from another node. STONITH also
has a role to play in the event that a clustered service cannot be
stopped. In this case, the cluster uses STONITH to force the whole node
offline, thereby making it safe to start the service elsewhere.


9.2. What STONITH Device Should You Use
---------------------------------------

It is crucial that the STONITH device can allow the cluster to
differentiate between a node failure and a network one. The biggest
mistake people make in choosing a STONITH device is to use remote power
switch (such as many on-board IMPI controllers) that shares power with
the node it controls. In such cases, the cluster cannot be sure if the
node is really offline, or active and suffering from a network fault.
Likewise, any device that relies on the machine being active (such as
SSH-based "devices" used during testing) are inappropriate.


9.3. Configuring STONITH
------------------------

  1.  Find the correct driver: pcs stonith list

  2.  Find the parameters associated with the device: pcs stonith
    describe <agent name>

  3.  Create a local config to make changes to pcs cluster cib
    stonith_cfg

  4.  Create the fencing resource using pcs -f stonith_cfg stonith create
    <stonith_id> <stonith device type> [stonith device options]

  5.  Set stonith-enable to true. pcs -f stonith_cfg property set
    stonith-enabled=true

  6.  If the device does not know how to fence nodes based on their
    uname, you may also need to set the special pcmk_host_map parameter.
    See man stonithd for details.

  7.  If the device does not support the list command, you may also need
    to set the special pcmk_host_list and/or pcmk_host_check parameters.
    See man stonithd for details.

  8.  If the device does not expect the victim to be specified with the
    port parameter, you may also need to set the special
    pcmk_host_argument parameter. See man stonithd for details.

  9.  Commit the new configuration. pcs cluster push cib stonith_cfg

  10.  Once the stonith resource is running, you can test it by
    executing: stonith_admin --reboot nodename. Although you might want
    to stop the cluster on that machine first.


9.4. Example
------------

Assuming we have an chassis containing four nodes and an IPMI device
active on 10.0.0.1, then we would chose the fence_ipmilan driver in step
2 and obtain the following list of parameters

# pcs stonith describe fence_ipmilanStonith options for: fence_ipmilan
  auth: IPMI Lan Auth type (md5, password, or none)  ipaddr: IPMI Lan IP to talk to
  passwd: Password (if required) to control power on IPMI device
  passwd_script: Script to retrieve password (if required)  lanplus: Use Lanplus
  login: Username/Login (if required) to control power on IPMI device
  action: Operation to perform. Valid operations: on, off, reboot, status, list, diag, monitor or metadata
  timeout: Timeout (sec) for IPMI operation
  cipher: Ciphersuite to use (same as ipmitool -C parameter)  method: Method to fence (onoff or cycle)  power_wait: Wait X seconds after on/off operation
  delay: Wait X seconds before fencing is started
  privlvl: Privilege level on IPMI device
  verbose: Verbose mode

from which we would create a STONITH resource fragment that might look
like this

# pcs cluster cib stonith_cfg# pcs -f stonith_cfg stonith create impi-fencing fence_ipmilan \ pcmk_host_list="pcmk-1 pcmk-2" ipaddr=10.0.0.1 login=testuser \
 passwd=acd123 op monitor interval=60s# pcs -f stonith_cfg stonith impi-fencing   (stonith:fence_ipmilan) Stopped

And finally, since we disabled it earlier, we need to re-enable STONITH.
At this point we should have the following configuration.

# pcs -f stonith_cfg property set stonith-enabled=true# pcs -f stonith_cfg propertydc-version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
cluster-infrastructure: corosync
no-quorum-policy: ignore
stonith-enabled: true

Now push the configuration into the cluster.

# pcs cluster push cib stonith_cfg



Configuration Recap
===================


A.1. Final Cluster Configuration
--------------------------------

# pcs resource Master/Slave Set: WebDataClone [WebData]
     Masters: [ pcmk-2 pcmk-1 ] Clone Set: dlm-clone [dlm]
     Started: [ pcmk-2 pcmk-1 ] Clone Set: ClusterIP-clone [ClusterIP] (unique)     ClusterIP:0        (ocf::heartbeat:IPaddr2) Started
     ClusterIP:1        (ocf::heartbeat:IPaddr2) Started
 Clone Set: WebFS-clone [WebFS]
     Started: [ pcmk-1 pcmk-2 ] Clone Set: WebSite-clone [WebSite]
     Started: [ pcmk-1 pcmk-2 ]# pcs resource rsc defaultsresource-stickiness: 100# pcs resource op defaultstimeout: 240s# pcs stonith impi-fencing   (stonith:fence_ipmilan) Started# pcs propertydc-version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
cluster-infrastructure: corosync
no-quorum-policy: ignore
stonith-enabled: true# pcs constraintLocation Constraints:
Ordering Constraints:
  ClusterIP-clone then WebSite-clone
  WebDataClone then WebSite-clone
  WebFS-clone then WebSite-clone
Colocation Constraints:
  WebSite-clone with ClusterIP-clone
  WebFS-clone with WebDataClone (with-rsc-role:Master)  WebSite-clone with WebFS-clone## pcs statusLast updated: Fri Sep 14 13:45:34 2012Last change: Fri Sep 14 13:43:13 2012 via cibadmin on pcmk-1
Stack: corosync
Current DC: pcmk-1 (1) - partition with quorum
Version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
2 Nodes configured, unknown expected votes
11 Resources configured.

Online: [ pcmk-1 pcmk-2 ]
Full list of resources:

 Master/Slave Set: WebDataClone [WebData]
     Masters: [ pcmk-2 pcmk-1 ] Clone Set: dlm-clone [dlm]
     Started: [ pcmk-1 pcmk-2 ] Clone Set: ClusterIP-clone [ClusterIP] (unique)     ClusterIP:0        (ocf::heartbeat:IPaddr2):       Started pcmk-1
     ClusterIP:1        (ocf::heartbeat:IPaddr2):       Started pcmk-2
 Clone Set: WebFS-clone [WebFS]
     Started: [ pcmk-1 pcmk-2 ] Clone Set: WebSite-clone [WebSite]
     Started: [ pcmk-1 pcmk-2 ] impi-fencing   (stonith:fence_ipmilan):        Started

In xml it should look similar to this.

<cib admin_epoch="0" cib-last-written="Fri Sep 14 13:43:13 2012" crm_feature_set="3.0.6" dc-uuid="1" epoch="47" have-quorum="1" num_updates="50" update-client="cibadmin" update-origin="pcmk-1" validate-with="pacemaker-1.2">  <configuration>    <crm_config>      <cluster_property_set id="cib-bootstrap-options">        <nvpair id="cib-bootstrap-options-dc-version" name="dc-version" value="1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0"/>        <nvpair id="cib-bootstrap-options-cluster-infrastructure" name="cluster-infrastructure" value="corosync"/>        <nvpair id="cib-bootstrap-options-no-quorum-policy" name="no-quorum-policy" value="ignore"/>        <nvpair id="cib-bootstrap-options-stonith-enabled" name="stonith-enabled" value="true"/>      </cluster_property_set>    </crm_config>    <nodes>      <node id="1" type="normal" uname="pcmk-1"/>      <node id="2" type="normal" uname="pcmk-2"/>    </nodes>    <resources>      <master id="WebDataClone">        <primitive class="ocf" id="WebData" provider="linbit" type="drbd">          <instance_attributes id="WebData-instance_attributes">            <nvpair id="WebData-instance_attributes-drbd_resource" name="drbd_resource" value="wwwdata"/>          </instance_attributes>          <operations>            <op id="WebData-interval-60s" interval="60s" name="monitor"/>          </operations>        </primitive>        <meta_attributes id="WebDataClone-meta_attributes">          <nvpair id="WebDataClone-meta_attributes-master-node-max" name="master-node-max" value="1"/>          <nvpair id="WebDataClone-meta_attributes-clone-max" name="clone-max" value="2"/>          <nvpair id="WebDataClone-meta_attributes-clone-node-max" name="clone-node-max" value="1"/>          <nvpair id="WebDataClone-meta_attributes-notify" name="notify" value="true"/>          <nvpair id="WebDataClone-meta_attributes-master-max" name="master-max" value="2"/>        </meta_attributes>      </master>      <clone id="dlm-clone">        <primitive class="ocf" id="dlm" provider="pacemaker" type="controld">          <instance_attributes id="dlm-instance_attributes"/>          <operations>            <op id="dlm-interval-60s" interval="60s" name="monitor"/>          </operations>        </primitive>        <meta_attributes id="dlm-clone-meta">          <nvpair id="dlm-clone-max" name="clone-max" value="2"/>          <nvpair id="dlm-clone-node-max" name="clone-node-max" value="1"/>        </meta_attributes>      </clone>      <clone id="ClusterIP-clone">        <primitive class="ocf" id="ClusterIP" provider="heartbeat" type="IPaddr2">          <instance_attributes id="ClusterIP-instance_attributes">            <nvpair id="ClusterIP-instance_attributes-ip" name="ip" value="192.168.0.120"/>            <nvpair id="ClusterIP-instance_attributes-cidr_netmask" name="cidr_netmask" value="32"/>            <nvpair id="ClusterIP-instance_attributes-clusterip_hash" name="clusterip_hash" value="sourceip"/>          </instance_attributes>          <operations>            <op id="ClusterIP-interval-30s" interval="30s" name="monitor"/>          </operations>        </primitive>        <meta_attributes id="ClusterIP-clone-meta">          <nvpair id="ClusterIP-globally-unique" name="globally-unique" value="true"/>          <nvpair id="ClusterIP-clone-max" name="clone-max" value="2"/>          <nvpair id="ClusterIP-clone-node-max" name="clone-node-max" value="2"/>        </meta_attributes>      </clone>      <clone id="WebFS-clone">        <primitive class="ocf" id="WebFS" provider="heartbeat" type="Filesystem">          <instance_attributes id="WebFS-instance_attributes">            <nvpair id="WebFS-instance_attributes-device" name="device" value="/dev/drbd/by-res/wwwdata"/>            <nvpair id="WebFS-instance_attributes-directory" name="directory" value="/var/www/html"/>            <nvpair id="WebFS-instance_attributes-fstype" name="fstype" value="gfs2"/>          </instance_attributes>          <meta_attributes id="WebFS-meta_attributes"/>        </primitive>        <meta_attributes id="WebFS-clone-meta"/>      </clone>      <clone id="WebSite-clone">        <primitive class="ocf" id="WebSite" provider="heartbeat" type="apache">          <instance_attributes id="WebSite-instance_attributes">            <nvpair id="WebSite-instance_attributes-configfile" name="configfile" value="/etc/httpd/conf/httpd.conf"/>            <nvpair id="WebSite-instance_attributes-statusurl" name="statusurl" value="http://localhost/server-status"/>          </instance_attributes>          <operations>            <op id="WebSite-interval-1min" interval="1min" name="monitor"/>          </operations>        </primitive>        <meta_attributes id="WebSite-clone-meta"/>      </clone>      <primitive class="stonith" id="impi-fencing" type="fence_ipmilan">        <instance_attributes id="impi-fencing-instance_attributes">          <nvpair id="impi-fencing-instance_attributes-pcmk_host_list" name="pcmk_host_list" value="pcmk-1 pcmk-2"/>          <nvpair id="impi-fencing-instance_attributes-ipaddr" name="ipaddr" value="10.0.0.1"/>          <nvpair id="impi-fencing-instance_attributes-login" name="login" value="testuser"/>          <nvpair id="impi-fencing-instance_attributes-passwd" name="passwd" value="acd123"/>        </instance_attributes>        <operations>          <op id="impi-fencing-interval-60s" interval="60s" name="monitor"/>        </operations>      </primitive>    </resources>    <constraints>      <rsc_colocation id="colocation-WebSite-ClusterIP-INFINITY" rsc="WebSite-clone" score="INFINITY" with-rsc="ClusterIP-clone"/>      <rsc_order first="ClusterIP-clone" first-action="start" id="order-ClusterIP-WebSite-mandatory" then="WebSite-clone" then-action="start"/>      <rsc_colocation id="colocation-WebFS-WebDataClone-INFINITY" rsc="WebFS-clone" score="INFINITY" with-rsc="WebDataClone" with-rsc-role="Master"/>      <rsc_colocation id="colocation-WebSite-WebFS-INFINITY" rsc="WebSite-clone" score="INFINITY" with-rsc="WebFS-clone"/>      <rsc_order first="WebFS-clone" id="order-WebFS-WebSite-mandatory" then="WebSite-clone"/>      <rsc_order first="WebDataClone" first-action="promote" id="order-WebDataClone-WebFS-mandatory" then="WebFS-clone" then-action="start"/>    </constraints>    <rsc_defaults>      <meta_attributes id="rsc_defaults-options">        <nvpair id="rsc_defaults-options-resource-stickiness" name="resource-stickiness" value="100"/>      </meta_attributes>    </rsc_defaults>    <op_defaults>      <meta_attributes id="op_defaults-options">        <nvpair id="op_defaults-options-timeout" name="timeout" value="240s"/>      </meta_attributes>    </op_defaults>  </configuration></cib>


A.2. Node List
--------------

The list of cluster nodes is automatically populated by the cluster.

Pacemaker Nodes:
 Online: [ pcmk-1 pcmk-2  ]


A.3. Cluster Options
--------------------

This is where the cluster automatically stores some information about the
cluster

  *  dc-version - the version (including upstream source-code hash) of
    Pacemaker used on the DC

  *  cluster-infrastructure - the cluster infrastructure being used
    (heartbeat or openais)

  *  expected-quorum-votes - the maximum number of nodes expected to be
    part of the cluster

and where the admin can set options that control the way the cluster
operates

  *  stonith-enabled=true - Make use of STONITH

  *  no-quorum-policy=ignore - Ignore loss of quorum and continue to host
    resources.

# pcs propertydc-version: 1.1.8-1.el7-60a19ed12fdb4d5c6a6b6767f52e5391e447fec0
cluster-infrastructure: corosync
no-quorum-policy: ignore
stonith-enabled: true


A.4. Resources
--------------

A.4.1. Default Options

A.4.2. Fencing

A.4.3. Service Address

A.4.4. DRBD - Shared Storage

A.4.5. Cluster Filesystem

A.4.6. Apache


A.4.1. Default Options

Here we configure cluster options that apply to every resource.

  *  resource-stickiness - Specify the aversion to moving resources to
    other machines

# pcs resource rsc defaultsresource-stickiness: 100


A.4.2. Fencing

# pcs stonith show impi-fencing   (stonith:fence_ipmilan) Started# pcs stonith show impi-fencingResource: impi-fencing
  pcmk_host_list: pcmk-1 pcmk-2
  ipaddr: 10.0.0.1
  login: testuser
  passwd: acd123


A.4.3. Service Address

Users of the services provided by the cluster require an unchanging
address with which to access it. Additionally, we cloned the address so
it will be active on both nodes. An iptables rule (created as part of the
resource agent) is used to ensure that each request only gets processed
by one of the two clone instances. The additional meta options tell the
cluster that we want two instances of the clone (one "request bucket" for
each node) and that if one node fails, then the remaining node should
hold both.

# pcs resource show ClusterIP-cloneResource: ClusterIP-clone
  ip: 192.168.0.120
  cidr_netmask: 32
  clusterip_hash: sourceip
  globally-unique: true  clone-max: 2
  clone-node-max: 2
  op monitor interval=30s


Note
----

TODO: The RA should check for globally-unique=true when cloned


A.4.4. DRBD - Shared Storage

Here we define the DRBD service and specify which DRBD resource (from
drbd.conf) it should manage. We make it a master/slave resource and, in
order to have an active/active setup, allow both instances to be promoted
by specifying master-max=2. We also set the notify option so that the
cluster will tell DRBD agent when it’s peer changes state.

# pcs resource show WebDataCloneResource: WebDataClone
  drbd_resource: wwwdata
  master-node-max: 1
  clone-max: 2
  clone-node-max: 1
  notify: true  master-max: 2
  op monitor interval=60s# pcs constraint ref WebDataCloneResource: WebDataClone
  colocation-WebFS-WebDataClone-INFINITY
  order-WebDataClone-WebFS-mandatory


A.4.5. Cluster Filesystem

The cluster filesystem ensures that files are read and written correctly.
We need to specify the block device (provided by DRBD), where we want it
mounted and that we are using GFS2. Again it is a clone because it is
intended to be active on both nodes. The additional constraints ensure
that it can only be started on nodes with active gfs-control and drbd
instances.

# pcs resource show WebFS-cloneResource: WebFS-clone
  device: /dev/drbd/by-res/wwwdata
  directory: /var/www/html
  fstype: gfs2# pcs constraint ref WebFS-cloneResource: WebFS-clone
  colocation-WebFS-WebDataClone-INFINITY
  colocation-WebSite-WebFS-INFINITY
  order-WebFS-WebSite-mandatory
  order-WebDataClone-WebFS-mandatory


A.4.6. Apache

Lastly we have the actual service, Apache. We need only tell the cluster
where to find it’s main configuration file and restrict it to running on
nodes that have the required filesystem mounted and the IP address
active.

# pcs resource show WebSite-cloneResource: WebSite-clone
  configfile: /etc/httpd/conf/httpd.conf
  statusurl: http://localhost/server-status
  master-max: 2
  op monitor interval=1min# pcs constraint ref WebSite-cloneResource: WebSite-clone
  colocation-WebSite-ClusterIP-INFINITY
  colocation-WebSite-WebFS-INFINITY
  order-ClusterIP-WebSite-mandatory
  order-WebFS-WebSite-mandatory



Sample Corosync Configuration
=============================

Example B.1. Sample corosync.conf for two-node cluster using a node list.

# Please read the corosync.conf.5 manual page
totem {
version: 2
secauth: off
cluster_name: mycluster
transport: udpu
}

nodelist {
  node {
        ring0_addr: pcmk-1
        nodeid: 1
  }
  node {
        ring0_addr: pcmk-2
        nodeid: 2
  }
}

quorum {
  provider: corosync_votequorum
}

logging {
  to_syslog: yes
}



Further Reading
===============

  *  Project Website http://www.clusterlabs.org

  *  Cluster Commands A comprehensive guide to cluster commands has been
    written by SuSE and can be found at:
    http://www.suse.com/documentation/sle_ha/book_sleha/?page=/documentation/sle_ha/book_sleha/data/book_sleha.html

  *  Corosync http://www.corosync.org



Revision History
================

Revision History

Revision 1

Mon May 17 2010

Andrew Beekhof

Import from Pages.app

Revision 2

Wed Sep 22 2010

Raoul Scarazzini

Italian translation

Revision 3

Wed Feb 9 2011

Andrew Beekhof

Updated for Fedora 13

Revision 4

Wed Oct 5 2011

Andrew Beekhof

Update the GFS2 section to use CMAN

Revision 5

Fri Feb 10 2012

Andrew Beekhof

Generate docbook content from asciidoc sources

Revision 6

Tues July 3 2012

Andrew Beekhof

Updated for Fedora 17

Revision 7

Fri Sept 14 2012

David Vossel

Updated for pcs



Index
=====


C

Creating and Activating a new SSH Key, Configure SSH


D

Domain name (Query), Short Node Names

Domain name (Remove from host name), Short Node Names


F

feedback

      contact information for this manual, We Need Feedback!


N

Nodes 

      Domain name (Query), Short Node Names

      Domain name (Remove from host name), Short Node Names

      short name, Short Node Names


S

short name, Short Node Names

SSH, Configure SSH
