I team up with Tim Serong and Andrew Beekhof for a tutorial at linux.conf.au 2012.

Ever wanted to know just which of your OSDs a RADOS object is currently stored in? Here’s how.

Suppose you’ve got an RBD device, named test. Then you can use the rbd info command to display which name prefix is used by the RADOS objects that make up …

Whenever a DRBD setup runs into a situation where the replication network is disconnected and fencing policy is set to dont-care (default), there is the potential risk of a split-brain. Even with resource level fencing or STONITH setup, there are corner cases that will end up in a split-brain.

When …

It’s simple and easy to get Pacemaker’s view of the status of members in a cluster – just invoke crm_mon. But what if you want to check on the cluster membership when Pacemaker is not running, or you want to make sure whether Corosync’s view of the cluster …

Often, people deploy the Pacemaker stack in virtual environments for purposes of testing and evaluation. In such environments, it’s easy to test Pacemaker’s fencing capabilities by tying in with the hypervisor.

This quick howto illustrates how to configure fencing for two virtual cluster nodes hosted on a libvirt …