Advice on using HA software on top of RHV

Latest response

Hi,

I need advice implementing High Availability software (pacemaker) to create an HA cluster for services on VMs on RHV.

We're using RHV4.2.

RHV provides HA for VMs, not for services on VMs.
We have to create a cluster of two VMs with a shared disk and use pacemaker, stonith ...etc to provide HA for the services and resources that comprises the cluster.

For fencing with Stonith we will use fence-rhevm.

We need some advice implementing this cluster, should we use VM HA (RHV) in conjunction with service HA (pacemaker)?
Is there any recommendations or things to avoid?

Regards.

Responses

Hello - i can't find any documentation but to me it would seem using VM HA is unnecessary. HA just restarts the VM if it detects that the VM dies (or the hypervisor it is running on dies). If you have fencing configured for your pacemaker cluster, then this should take care of it anyway.

On thing to keep in mind though is that ovirt-engine must keep be kept running. Your VM's will run fine with ovirt-engine down, but they won't be able to fence other nodes (if needed). If fencing 'fails', then the cluster generally locks up or loses functionality.

and you should make sure the clustered service vms don't run on the same hypervisor. I guess anti-affinity could solve that.