*** (0.28) *** Re: [Linux-HA] quorum server not available

[Alan Robertson]

Andreas Kurz wrote:
> On 2/24/07, Alan Robertson <alanr at unix.sh> wrote:
>> Sebastian Reitenbach wrote:
>> > Hi,
>> >>> did not showed a quorumd running, the hostcache file did only
>> contain the
>> > five
>> >>> uuids, and
>> >>> I was connected to the DC with the gui, and I read there without
>> quorum,
>> > which I
>> >>> also read
>> >>> in the messages log file.
>> >> Oh....
>> >>
>> >> One very important thing... Quorumd is not supposed to run on your
>> >> cluster at all...
>> > that this is not supposed to be is new to me, but we already thought
>> about that.
>> > We
>> > thought that defining an IP resource and let the quorum IP resolve
>> to this IP
>> > resource so
>> > that it can live on any host, but we just saw with some nodes, the
>> one with the
>> > quorum IP
>> > running, died, and the resource was stuck on the dead node, because
>> the rest of
>> > the
>> > cluster lost quorum. nevertheless we thought plan to run another two
>> node
>> > cluster, which
>> > shall have an IP resource that it could become the quorum for the
>> other cluster.
>>
>> You can indeed have one cluster act as quorum server for another cluster
>> - but you should NEVER run more than one quorum server in the same
>> cluster - and they should be resources - not started through ha.cf.
>>
>> But, it definitely won't do what I'm pretty sure you're expecting it
>> to do.
>>
>> And, you almost certainly don't want to run a quorum server as your
>> primary quorum method - because it becomes a single point of failure.
>>
>> The normal way to configure it is as a secondary (tie-breaker) quorum
>> method.
> 
> Is it possible to configure stonith as primary method and in case the
> stonith action fails to rely in a second step on the quorumd
> information to failover the resources?

The quorumd is tied in to quorum.

If you don't have quorum (by the configured methods), it won't try to
STONITH anyone.  This is to keep the two sides from STONITHing each other.

You can configure both the quorumd and also STONITH, but they're used in
the opposite order.

There's a general expectation that if you configure STONITH that it
ought to succeed.

At one point I asked Andrew to consider making it go ahead after STONITH
had failed, if the right configuration options were set.  I don't
remember exactly what became of that request.

But it would be useful to understand exactly why you want to do this -
to see if there's some perfectly reasonable way to do what you want in
the product as it stands today.

-- 
    Alan Robertson <alanr at unix.sh>

"Openness is the foundation and preservative of friendship...  Let me
claim from you at all times your undisguised opinions." - William
Wilberforce