[ClusterLabs] Two node cluster without fencing and no split brain?
Jehan-Guillaume de Rorthais
jgdr at dalibo.com
Thu Jul 22 05:42:54 EDT 2021
On Wed, 21 Jul 2021 12:45:40 -0400
Digimer <lists at alteeve.ca> wrote:
> On 2021-07-21 3:26 a.m., Jehan-Guillaume de Rorthais wrote:
> > Hi,
> > On Wed, 21 Jul 2021 04:28:30 +0000 (UTC)
> > Strahil Nikolov via Users <users at clusterlabs.org> wrote:
> >> Hi,
> >> consider using a 3rd system as a Q disk. Also, you can use iscsi from that
> >> node as a SBD device, so you will have proper fencing .If you don't have a
> >> hardware watchdog device, you can use softdog kernel module for that. Best
> > Having 3 nodes for quorum AND watchdog (using softdog in last resort) is
> > enough, isn't it?
> > But yes, having a shared storage to add a SBD device is even better.
> > Regards,
> The third node with storage-based death is a way of creating a fence
Yes, poison pill.
> It works because it's fencing, not because it's quorum.
That's not what I said. Two node + sbd is safe. OK.
My consideration/question was: 3 nodes + watchdog, without storage-based death,
looks good enough to me. Do I miss something?
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