[rhn-users] RHCS quorum/multipath

[Frank Clements]

Hello list,

I'm in the process of setting up a two node cluster attached to a Dell
MD3000i.  Both nodes are connected via two switches to provide full backend
redundancy.  The dell MPP drivers are installed and reporting everything as
Ok, path failover is working as expected (although longer than I would
expect).

The issue I'm running into is that in the event of path failure CMAN
complains about losing contact with the quorum and eventually fences the
node which lost the path.  I've attempted tuning the totem and
quorum_dev_poll to higher values (all configs/logs attached).  The quorum is
slightly lower than both.  I actually followed the RH KB doc 2882 which
states to set the quorum timeout (interval * tko) to a value 1.7x larger
than the multipath failover value and totem to a value 2.7x greater.  

Now, there is little no documentation from Dell on what the values in
mpp.conf mean.  I _think_ I've reset these to some fairly low values, but
have since reverted back to the default config in the initrd image.  In the
attached messages file I shutdown one of the backend interfaces to simulate
path failure, after about a minute the node is evicted and fenced.  I just
can't seem to get all the values to line up to allow path failover without
node fencing.

I'm wondering if anyone else has experienced this and how it's resolved?
I'm at a loss at this point so any help is appreciated.

Frank Clements
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