On Thu, 2013-03-14 at 16:26 +0100, Lars Marowsky-Bree wrote:
> On 2013-03-14T09:44:11, "GGS (linux ha)" <[email protected]> wrote:
> 
> That's fine. But the cluster software really assumes that only one
> instance of it is running per server - said instance can then manage
> multiple software stacks, though.

Got it. That's what I was asking.
> 
> No. Pacemaker allows resources and groups (probably the equivalent of
> your "stacks") to be individually managed.
> 
> If you want to bring down pacemaker itself for maintenance, you'd detach
> via maintenance mode, stop, update, restart, reattach.

I'll have to dig in deeper, it may be a possibility. We really
would like to move away from the in-house built solution.
> 
> But there is a point where this matters, namely IO fencing/STONITH. In
> case of a real server failure, you don't want 200+ independent fencing
> processes to trigger.

Believe it or not, I would actually rather have the 200+
fencing processes to trigger. But that is not a
requirement. I just need to ensure failover completes
within the allowed time.

> 
> Yes. That's called multitasking/virtualization/cloud. We get that. ;-)

Multitasking yes, virtualization no, that's another discussion :-)
> 
> But just like you only have "one kernel" per physical server, you also
> only have one cluster stack that then manages multiple stacks. We even
> got ACLs so that you can grant people access to only the bits they're
> allowed to manage, etc.
> 
> What you plan - running multiple heartbeat v1 setups on one node - will
> not work reliably. Running multiple pacemaker instances per node/OS
> image will not work either.

That's what I thought. The emails from 2009 seemed to indicate
that it was possible to run multiple instances. 

I asked because I suspected that it really wasn't the case. Thanks
for confirming it. I'll dig deeper into pacemaker and see how I
can make it work for our use case.

One quick question on pacemaker. If I add a new stack, do I need
to bring the old ones down (or fail them) to add it to pacemaker? 
>From your comment above it seems that I wouldn't, but I just want 
to make sure.

Thanks,

Alberto


> 
> 
> Regards,
>     Lars
> 
-- 
Alberto Alonso                        Global Gate Systems LLC.
(512) 351-7233                        http://www.ggsys.net
Monitoring the metrics that are important to you in real time

_______________________________________________
Linux-HA mailing list
[email protected]
http://lists.linux-ha.org/mailman/listinfo/linux-ha
See also: http://linux-ha.org/ReportingProblems

Reply via email to