[Pacemaker] order constraint based on any one of many

[Patrick Irvine]

-----Original Message-----
From: Andrew Beekhof [mailto:andrew at beekhof.net] 
Sent: Friday, August 27, 2010 7:24 AM
To: The Pacemaker cluster resource manager
Subject: Re: [Pacemaker] order constraint based on any one of many

On Tue, Aug 24, 2010 at 4:03 AM, Patrick Irvine <pirv at cybersites.ca> wrote:
> Hi Vishal & list,
>
> Thanks for the info.  Unfortuantly that won't due since this clone (glfs)
is
> the actual mounting of the user's home directorys and needs to be mounted
> whither the local glfsd(server) is running or not.  I do think I have a
> solution, it's some what of a hack.
>
> If I turn my glfsd-x (servers) into a single master with multiple slaves
> (cloned resources) then I could order the glfs(client) clone after the
> master starts
>
> ie.
>
> order glfs-after-glfsd-ORDER    inf: clone-glfsd:master clone-glfs
>
> this would achive what I want I think,
>
> I would ofcourse have to insure that even if only one of the glfs-x
servers
> is running, it would be master.
>
> any comments?

that should work, though i dont really understand why glfsd cant just
be a regular clone.
why would it need to be a master/slave?

also a possibility is to clone the glfsd group (ie. glfsd-1-GROUP) -
the trick is making the IPaddr agent factor in the clone number when
deciding which IP to start.
there should be something like that in IPaddr or IPaddr2 but it may
not be fully baked.

> (and was I understandable?)

yes :-)

Hi, and thanks for the response.

The issue is this.  Glfs must be restricted from starting until at least one
of the glfsd clones has started.  The glfsd clones provide the backed
storage for the glfs mounts.  So glfsd doesn't really need to be a M/S.
This is just a way I came up with to make glfs wait for any single glfsd as
opposed to waiting for all glfsd clones.

What I really need is some order constraint ( or some other mechanism) that
is like the logic below (to use some C syntax)

If ( glfsd-1 || glfsd-2 || glfsd-3 || glfsd-4 ) then start glfs-clones

Thanks again for the reply

Pat

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