On Sat, Nov 5, 2022 at 9:45 PM Jehan-Guillaume de Rorthais via Users < users@clusterlabs.org> wrote:
> On Sat, 5 Nov 2022 20:53:09 +0100 > Valentin Vidić via Users <users@clusterlabs.org> wrote: > > > On Sat, Nov 05, 2022 at 06:47:59PM +0000, Robert Hayden wrote: > > > That was my impression as well...so I may have something wrong. My > > > expectation was that SBD daemon should be writing to the /dev/watchdog > > > within 20 seconds and the kernel watchdog would self fence. > > > > I don't see anything unusual in the config except that pacemaker mode is > > also enabled. This means that the cluster is providing signal for sbd > even > > when the storage device is down, for example: > > > > 883 ? SL 0:00 sbd: inquisitor > > 892 ? SL 0:00 \_ sbd: watcher: /dev/vdb1 - slot: 0 - uuid: > ... > > 893 ? SL 0:00 \_ sbd: watcher: Pacemaker > > 894 ? SL 0:00 \_ sbd: watcher: Cluster > > > > You can strace different sbd processes to see what they are doing at any > > point. > > I suspect both watchers should detect the loss of network/communication > with > the other node. > > BUT, when sbd is in Pacemaker mode, it doesn't reset the node if the > local **Pacemaker** is still quorate (via corosync). See the full chapter: > «If Pacemaker integration is activated, SBD will not self-fence if > **device** > majority is lost [...]» > > https://documentation.suse.com/sle-ha/15-SP4/html/SLE-HA-all/cha-ha-storage-protect.html > > Would it be possible that no node is shutting down because the cluster is > in > two-node mode? Because of this mode, both would keep the quorum expecting > the > fencing to kill the other one... Except there's no active fencing here, > only > "self-fencing". > Seems not to be the case here but for completeness: This fact should be recognized automatically by sbd (upstream since some time in 2017 iirc) and instead of checking quorum sbd would then check for presence of 2 nodes with the cpg-group. I hope corosync prevents 2-node & qdevice set at the same time. But even in that case I would rather expect unexpected self-fencing instead of the opposite. Klaus > > To verify this guess, check the corosync conf for the "two_node" parameter > and > if both nodes still report as quorate during network outage using: > > corosync-quorumtool -s > > If this turn to be a good guess, without **active** fencing, I suppose a > cluster > can not rely on the two-node mode. I'm not sure what would be the best > setup > though. > > Regards, > _______________________________________________ > Manage your subscription: > https://lists.clusterlabs.org/mailman/listinfo/users > > ClusterLabs home: https://www.clusterlabs.org/ >
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