On 2008-03-07T20:11:46, Atanas Dyulgerov <[EMAIL PROTECTED]> wrote:
> Hm, I left with the impression openais is part of the red hat cluster suite
> in some way: http://sources.redhat.com/cluster/faq.html#what
Check question 12 ;-)
> >That's something the resource agents would need to do. And as far as I
> >know, openAIS does not do the resource level locking you refer to; but
> >Pacemaker internally ensures exclusive access to them.
> Yes, Pacemaker should support resource locking.
But it does. Pacemaker already "locks" the resources to one node, and
orders fencing, STONITH, start/stop etc as needed to ensure that
resources are not running where they aren't allowed to.That's what a
cluster resource manager is all about.
I'm not sure what more you are asking for?
> So you are saying that Heartbeat replaces successfully all of the above? Can
> OCFS2 get its membership information from Heartbeat? Does Heartbeat CRM
> controls OCFS2 distributed lock manager?
>
> If true, could you send me some links for that? Patches, docs, sample
> configuration in Heartbeat? Thanks!
We've got that working in SLES10. The patches are all open source (of
course), and the user-space membership code is supposedly merged
upstream in OCFS2 by now.
On the heartbeat/Pacemaker side, it is as easy as configuring the
Filesystem resource for the ocfs2 mount, just as a clone.
> >That is going to work just fine, though if you're using GFS2 or OCFS2 on
> >top of GNBD or iSCSI (because you don't have a SAN, presumably), I'd
> >really wonder why you're not directly using NFS?
> Hm? GFS and GNBD works with red hat cluster suite only?
GFS yes; GFS2 will eventually work with Pacemaker as well.
> I don't have SAN. I'm looking for a cheaper solution. The reason I'm
> not using NFS is the slower performance compared to the fastest GNBD
> and iSCSI.
Have you _benchmarked_ that for your workload? iSCSI/GNBD are
block-level protocols, that means a higher overhead over the network.
And because OCFS2/GFS2 do their own locking, the nodes also have a fair
bit of additional internode communication.
> Also a very specific service application is running on the cluster and
> it does not get along with NFS very well.
What kind of features does it use that don't get along with NFS? In
theory, NFSv4/3 should be 1:1 compatible?
> To lock the network block device if node fails to bring down the
> service application or if for any reason the cluster software fails on
> that node. In that case the application will be started on a passive
> node and the cluster might end up with two nodes which try to access
> the same data.
Pacemaker/Heartbeat handle this through fencing/STONITH. It'd of course
be fatal if not.
> >> - OCFS2 is not completely stable and it is driven by its own cluster
> >OCFS2 is not completely stable?
> That's what I read on various forums... not my personal experience.
Ah. Rumors. ;-)
Regards,
Lars
--
Teamlead Kernel, SuSE Labs, Research and Development
SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg)
"Experience is the name everyone gives to their mistakes." -- Oscar Wilde
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