[Pacemaker] Two-node cluster fencing

[Michael Schwartzkopff]

Am Montag, 21. Oktober 2013, 10:28:53 schrieb Timm Bordeman:
> Hi,
> 
> I'm building a two-node cluster based on XenServer, Pacemaker and DRBD. All
> needed resources are configured and correctly handled by pacemaker, but
> currently I'm struggling with stonith / fencing.
> 
> Both physical servers are running XenServer and a couple of virtual machines
> which are being mirrored. For example, on each servers is an Apache-VM
> running which share a data partition over DRBD. I configured fencing over
> XEN, which is restarting any faulty VM reliable, as long as both physical
> servers are working correctly.
> 
> Unfortunately fencing doesn't work when a server that hosts a faulty virtual
> machine is powered off or not reachable over the network. In this case
> pacemaker does not promote the DRBD partition on the second / passive
> virtual machine to the primary partition. Other resources, like the apache
> server, won't get started. I know that this is an expected behaviour of
> Pacemaker and DRBD, but I'm not sure what is needed to make the failover
> reliable even in the case of a completely broken physical server. Fencing
> by issuing a reboot of the broken server obviously is not an option since
> the server wouldn't come up due to a hardware defect.
> 
> I appreciate any help on this.
> 
> Thanks,
> Tim

You considered that quorum does not work in a two-node cluster (option no-
quorum-policy="ignore")?

The other possibility is that fencing does not reach the other server to run 
its commands successful. Please check the logs and give more detail on your 
setup. What do you want to acchieve? Konfig? Logs?


-- 
Dr. Michael Schwartzkopff
Guardinistr. 63
81375 München

Tel: (0163) 172 50 98