[Pacemaker] offtopic scalable block-device

[Lars Marowsky-Bree]

On 2012-03-16T11:28:36, Florian Haas <florian at hastexo.com> wrote:

> > is there a reason for integrating ceph with pacemaker? ceph does
> > internal monitoring of OSTs etc anyway, doesn't it?
> Assuming you're referring to OSDs, yes it does. It does automatic
> failover for MDSs (if you use them) and MONs too. But it currently has
> no means of recovering an osd/mds/mon daemon in place when it crashes,
> and that's what those RAs do. Really trivial.

Yes, I need to stop calling them OSTs, but that's what object storage
targets were called before ceph came along ;-) Sorry. Yes, of course, I
mean OSDs.

Would this not be more readily served by a simple while loop doing the
monitoring, even if systemd/upstart aren't around? Pacemaker is kind of
a heavy-weight here.

> The ocf:ceph:rbd RA by contrast serves an entirely different purpose,
> and I currently don't see how _that_ would be replaced by upstart or
> systemd. Unless either of those becomes so powerful (and
> cluster-aware) that we don't need Pacemaker at all anymore, but I
> don't see that happen anytime soon.

Agreed. I was mostly curious about the server-side. Thanks for the
clarification.


Regards,
    Lars

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