In this article I will explains how to set up and maintain an Active/Passive Cluster, using Pacemaker with Corosync with DRBD replication.
We have two nodes (same hardware), one active and another in passive mode. If the active node goes down, the passive one will automatically take its position and all running services.
This article was written complete for and with Debian 6-squeeze (With a lot of luck you could bring it to run on Ubuntu)
1. Basic notes
/dev/vda1 System / ext4
/dev/vda5 reserved for DRBD – empty
/dev/vda6 swap area
Cluster IP: 192.168.2.100
We need this cluster IP to reach currently active node.
This is a physical network structure of the cluster: