Creating a two-node CentOS 6 cluster with floating IP using Pacemaker and Corosync

These are my old instructions for creating a Linux cluster with floating IP on versions of CentOS prior to 6.4.

If you’re using CentOS 6.4 or higher, you need my updated post for creating a cluster with CMAN and Pacemaker.

Installation and configuration

Install the required packages and prepare the configuration file:

yum install pacemaker
cp /etc/corosync/corosync.conf.example /etc/corosync/corosync.conf

Change bindnetaddr to your network address (e.g. in
/etc/corosync/corosync.conf. Create /etc/corosync/service.d/pcmk and put
the Pacemaker startup config into it:

service {
        name: pacemaker
        ver: 1 

Start corosync and pacemaker:

service corosync start
service pacemaker start

Make sure they start on boot:

chkconfig corosync on
chkconfig pacemaker on

Repeat all of the above on the second node. Then disable STONITH on the primary node:

crm configure property stonith-enabled=false

Add a floating IP on the primary node (change IP address and netmask as

crm configure primitive ClusterIP ocf:heartbeat:IPaddr2 params ip= cidr_netmask=24 op monitor interval=30s

Disable quorum on the primary node (necessary for running only two nodes):

crm configure property no-quorum-policy=ignore

Prevent resources from moving back after a node recovers:

crm configure rsc_defaults resource-stickiness=100

Use the commands in the Administration section below to ensure that the
floating IP is on the correct machine – if this is not the case then
temporarily shut down Pacemaker on whichever machine has the floating IP so
that it moves across to the desired node:

service pacemaker stop


Display the current configuration:

crm configure show

Status monitor:

crm status

Show which node has the cluster IP:

crm resource status ClusterIP

Reset the config to default:

cibadmin -E --force

Verify that there are no problems with the current config:

crm_verify -L