[ClusterLabs] Two nodes cluster issue

[Klaus Wenninger]

On 07/24/2017 05:15 PM, Tomer Azran wrote:
> I still don't understand why the qdevice concept doesn't help on this
> situation. Since the master node is down, I would expect the quorum to
> declare it as dead.
> Why doesn't it happens?

That is not how quorum works. It just limits the decision-making to the
quorate subset of the cluster.
Still the unknown nodes are not sure to be down.
That is why I suggested to have quorum-based watchdog-fencing with sbd.
That would assure that within a certain time all nodes of the
non-quorate part
of the cluster are down.

>
>
>
> On Mon, Jul 24, 2017 at 4:15 PM +0300, "Dmitri Maziuk"
> <dmitri.maziuk at gmail.com <mailto:dmitri.maziuk at gmail.com>> wrote:
>
>     On 2017-07-24 07:51, Tomer Azran wrote:
>     > We don't have the ability to use it.
>     > Is that the only solution?
>
>     No, but I'd recommend thinking about it first. Are you sure you will 
>     care about your cluster working when your server room is on fire? 'Cause 
>     unless you have halon suppression, your server room is a complete 
>     write-off anyway. (Think water from sprinklers hitting rich chunky volts 
>     in the servers.)
>
>     Dima
>
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-- 
Klaus Wenninger

Senior Software Engineer, EMEA ENG Openstack Infrastructure

Red Hat

kwenning at redhat.com   

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