Doubt regarding HA fence on Proxmox

[DANILO MONTAGNA]

Hi,

I use three node cluster with proxmox 6 and CephRDB for virtual machines.

Is fence really necessary for virtual machines running over a ceph rdb cluster? no other shared resources exist.. soh that's why I'm confusing about the fence requirement on this HA cluster.

My self understand about CEPH is that it does not depend on Proxmox HA (PACEMAKER) to work. So, fencing is this case would not be necessary, since CEPH has built-in services to control the read/write locking for shared storage and protect itself against access corruption.

Anyone could explain if I'm wrong?

 

[dietmar]

My self understand about CEPH is that it does not depend on Proxmox HA (PACEMAKER) to work.

FYI, Proxmox HA does not use PACEMAKER.

 

[Alwin]

My self understand about CEPH is that it does not depend on Proxmox HA (PACEMAKER) to work. So, fencing is this case would not be necessary, since CEPH has built-in services to control the read/write locking for shared storage and protect itself against access corruption.

Not in all cases, eg. krbd containers don't have locking (yet). And I suppose it is not the only shared resource used on the cluster. Better be more cautious with data then not.

More general, for HA to work fencing is needed to make sure that a resource is in its desired state only once on the cluster.