[Linux-HA] Quorum problem with 3-node cluster
mark at netexpo.nl
Thu Oct 1 10:33:09 MDT 2009
Dejan Muhamedagic wrote:
> On Thu, Oct 01, 2009 at 04:45:45PM +0200, Mark Hunting wrote:
>> Sorry for not mentioning I use Heartbeat 2.1.3 from the Debian Lenny
>> repository, in crm configuration.
>> Mark Hunting wrote:
>>> I have set up a 3-node cluster. Works perfectly, but when I shut one
>>> node down the other two lose quorum, and shut down their resources (!)
>>> because no-quorum-policy is set to 'stop' like it should.
>>> I have no idea why the quorum is lost, this really should not happen as
>>> the remaining two nodes are still the majority. crm_mon shows them
>>> online and they can talk to each other. Only the quorum is lost,
>>> have_quorum is "false" until the third node comes up again.
>>> Can anybody tell me how this is possible, or give me some command that
>>> can help me investigate this?
> ccm_tool (or similar, can't recall the name exactly) can show you
> what a node thinks its partition looks like. Otherwise, look at
> the ccm lines in the logs, though they may be really hard to
> figure out.
Thanks a lot! It just came to my mind that I changed the three node
names today in ha.cf, and this problem started to occur afterwards. I
think the cluster still remembers the three old names next to the new
ones. I guess it now 'thinks' it has six nodes instead of three, and
that may be an explanation for this behaviour I'm seeing (although then
with 3 of the 6 nodes online it also shouldn't get a quorum imo, but it
does). crm_admin shows only 3 nodes however, that's a bit strange. I
can't access the cluster right now, but I'll try to figure out more
tomorrow. There should be a way to force the removal of the old node
names (ideas anyone?)
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