Setup basic pacemaker cluster on RHEL 6
by Zamir
This is a note to setup a basic RHEL 6 cluster environment without any additional cluster resources. In this example I am using two VMs.
0.Configure /etc/hosts on both of the VMs, so that they can access each other by hostname. I added the following lines to /etc/hosts. This should be done on all nodes.
192.168.122.111 rhel6-pcs-cluster-n1 192.168.122.112 rhel6-pcs-cluster-n2
1.Install related packages. This requires subscription for RHEL 6 High Availability Add On, or equvaliance if you are using community driven RHEL derivatives like CentOS. This should be done on all nodes.
sudo yum install pacemaker pcs
2.Start related daemon This should be done on all nodes.
sudo service pcsd start
sudo chkconfig pcsd on
sudo service corosync start
sudo chkconfig corosync on
3.Configure the password for cluster authentication. This should be the same for all nodes!
sudo passwd hacluster
4.Config firewall. In this case, this environment is for testing purpose, so I simply disabled iptables. This should be done on all nodes.
sudo service iptables stop
sudo chkconfig iptables off
5.Configure cluster authentication. Execute the following on ONE NODE.
sudo pcs cluster auth rhel6-pcs-cluster-n1 rhel6-pcs-cluster-n2
It should ask you for username and password. Use the user hacluster and password you set in step 3.
After this, you should see something like the following
rhel6-pcs-cluster-n1: Authorized
rhel6-pcs-cluster-n2: Authorized
From now on, you can configure it on this machine (instead of doing it on all nodes!)
6.Create the cluster
sudo pcs cluster setup --name pcscluster rhel6-pcs-cluster-n1 rhel6-pcs-cluster-n2
7.Starting the cluster
sudo pcs cluster start --all
Then you can check cluster status in any of the nodes using
sudo pcs status
Note: Each time you added a new node (or created the cluster), it will take sometine for all nodes to go online.
This is basically done.
References:
- https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/configuring_the_red_hat_high_availability_add-on_with_pacemaker/
- https://www.digitalocean.com/community/tutorials/how-to-set-up-an-apache-active-passive-cluster-using-pacemaker-on-centos-7