[ClusterLabs] issue during Pacemaker failover testing

[Andrei Borzenkov]

On 30.08.2023 19:23, David Dolan wrote:
>>
>> Use fencing. Quorum is not a replacement for fencing. With (reliable)
>> fencing you can simply run pacemaker with no-quorum-policy=ignore.
>>
>> The practical problem is that usually the last resort that will work
>> in all cases is SBD + suicide and SBD cannot work without quorum.
>>
>> Ah I forgot to mention I do have fencing setup, which connects to Vmware
> Virtualcenter.
> Do you think it's safe to set that no-quorum-policy=ignore?

fencing is always safe. fencing guarantees that when nodes take over 
resources of a missing node, the missing node is actually not running 
any of these resources. Yes, if fencing fails resource won't be taken 
over but usually it is better than possible corruption. Quorum is 
entirely orthogonal to that. If your two nodes lost connection to the 
third node, they will happily take over resources whether the third node 
already stopped them or not.

If you actually mean "is it guaranteed that the survived node will 
always be able to take over resources from other nodes" - no, it depends 
on network connectivity, if connection to VC is lost (or if anything bad 
happens during communication with VC, like somebody changed password you 
use) fencing will fail and resources won't be taken over.