[Pacemaker] Configuring a cluster for asymmetric operation

[Brad Jones]

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