[Pacemaker] Configuring a cluster for asymmetric operation

[David Coulson]

Pacemaker needs to be able to monitor on all nodes. Maybe if you install 
drbd on the third node but don't configure anything monitor will 
correctly report it is not running over there, and your location rules 
will stop it from even trying.

Or just change the RA for DRBD to report not running instead of not 
installed - I had to do that in a few cases where the RA needed the 
config file to exist, but the file was on a filesystem managed by 
pacemaker. Seems to work ok, and isn't impacting the cluster at all.

On 6/8/12 3:36 AM, Brad Jones wrote:
> I have a cluster with three nodes, A B and C.  A and B can basically
> stand in for one another; they run a DRBD master/slave set, and
> failure of A where most things run normally fires up services on B.
>
> C helps arbitrate quorum and runs Stonith plugins.  I've written
> location rules to prohibit most of the production services from
> running on node C.
>
> Problem is, the DRBD RA tries to monitor on node C, even though DRBD
> isn't even installed.  (It fails, helpfully, "not installed.")  I'm
> stuck with a slowly-incrementing failcount on C.
>
> When I give all services a default location rule and set
> symmetric-cluster="false", some of the resources stay running on A but
> most of the important ones stop.
>
> This was raised back in 2010 here:
> <http://oss.clusterlabs.org/pipermail/pacemaker/2010-April/005873.html>
> but I can't find much more about this issue on the web and there's
> only passing mention of it in the Pacemaker documentation.
>
> Bottom line: What's required to correctly configure a cluster with
> symmetric-cluster set to false?
>
> FYI I'm on pacemaker 1.1.6, heartbeat 3.0.5, on Ubuntu 10.04.
>
> Thanks!  Brad
> --
> Brad Jones
> Brad at Jones.name
> Mobile: 303-219-0795
>
> _______________________________________________
> Pacemaker mailing list: Pacemaker at oss.clusterlabs.org
> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
>
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org