On 2019-04-07T12:06:40, Andrei Borzenkov <[email protected]> wrote:
> After reading sources and experimenting I still do not see how it can > help in two node cluster. In this case SBD will assume both nodes are > out of quorum and both nodes will commit suicide. It helps by not making a single SBD device a single point of failure in the cluster. That's particularly relevant in 2 node clusters which can more readily experience loss of quorum temporarily due to loss of connectivity. You're right it's not a perfect choice. Multiple SBDs or 2+ nodes are preferable. > Pacemaker integration may be useful in two node cluster as backup to > avoid suicide in case of temporary disk access issues, but we still need > disk as primary channel with all associated considerations for proper > timeouts. Right. If they do lose the device access in addition to being in a non-quorate or dirty state, the node(s) will still suicide. So even if it can't read the poison pill from the surviving other node, it'll self-fence and the other node can trust this and proceed. That is, at least, the idea. -- SUSE Linux GmbH, GF: Felix Imendörffer, Mary Higgins, Sri Rasiah, HRB 21284 (AG Nürnberg) "Architects should open possibilities and not determine everything." (Ueli Zbinden) _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
