he following will install and configure DRBD, OpenAIS, Pacemaker and Xen on OpenSUSE 11.1 to provide highly-available virtual machines. This setup does not utilize Xen's live migration capabilities. Instead, VMs will be started on the secondary node as soon as failure of the primary is detected. Xen virtual disk images are replicated between nodes using DRBD and all services on the cluster will be managed by OpenAIS and Pacemaker. The following setup utilizes DRBD 8.3.2 and Pacemaker 1.0.4. It is important to note that DRBD 8.3.2 has come a long way since previous versions in terms of compatibility with Pacemaker. In particular, a new DRBD OCF resource agent script and new DRBD-level resource fencing features. This configuration will not work with older releases of DRBD.