[ClusterLabs] shutdown of 2-Node cluster when power outage

[Andrei Borzenkov]

20.04.2019 22:29, Lentes, Bernd пишет:
> 
> 
> ----- Am 18. Apr 2019 um 16:21 schrieb kgaillot kgaillot at redhat.com:
> 
>>
>> Simply stopping pacemaker and corosync by whatever mechanism your
>> distribution uses (e.g. systemctl) should be sufficient.
> 
> That works. But strangely is that after a reboot both nodes are
> shown as UNCLEAN. Does the cluster not remeber that it has been shutdown cleanly ?

No. Pacemaker does not care what state cluster was during last shutdown.
What matters is what state cluster is now.

> Problem is that after starting pacemaker and corosync on one node the other
> is fenced because of that. (pacemaker and corosync aren't started automatically
> by systemd).
> 

That is correct and expected behavior. If node still did not appear
after timeout, pacemaker assumes node is faulted and attempts to proceed
with remaining nodes (after all, it is about _availability_ and waiting
indefinitely means resources won't be available). For this it needs to
ascertain state of missing node, so pacemaker attempts to stonith it.
Otherwise each node could attempt to start resources resulting in split
brain and data corruption.

Either start pacemaker on all nodes at the same time (with reasonable
fuzz, doing "systemctl start pacemaker" in several terminal windows
sequentially should be enough) or set wait_for_all option in corosync
configuration. Note that with if you have two node cluster, two_node
corosync option also implies wait_for_all.