[Pacemaker] Configuring a cluster for asymmetric operation

[David Vossel]

----- Original Message -----
> From: "Jake Smith" <jsmith at argotec.com>
> To: "The Pacemaker cluster resource manager" <pacemaker at oss.clusterlabs.org>
> Sent: Friday, June 8, 2012 10:45:59 AM
> Subject: Re: [Pacemaker] Configuring a cluster for asymmetric operation
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> David,
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> Just so I'm clearer (when I run into this issue...)
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> You have to have all of the supporting software for each resource
> installed (i.e. drbd, nfs, mysql, or whatever) not just the RA's?
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> If you have the RA's installed you'd get "not installed" but that is
> not sufficient for Pacemaker to assume it's not running? I would
> think that not installed would be can't be running but... ;-)
>

My understanding is this. If you have symmetric-cluster == true, both the RA scripts and all the software the RA scripts use should be installed on every node in the cluster.  An RA returning 'not installed' will cause failures if symmetric-cluster == true.  This is why Brad had to install the drbd software on server C with a skeleton config even though the software will never run.

If symmetric-cluster == false, it appears that it is sufficient enough to just have the RA scripts installed.  In that case 'not installed' is treated the same as if the resource isn't running.  This bit is based on my analysis of the code.  I have not actually tested this scenario out, but this is what I would expect to happen.

-- Vossel

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> Thanks!
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> Jake
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