[Pacemaker] Backup ring is marked faulty

[Devin Reade]

--On Thursday, August 04, 2011 03:21:58 PM +0200 Sebastian Kaps
<sebastian.kaps at imail.de> wrote:

>  On Thu, 4 Aug 2011 08:31:07 +0200, Tegtmeier.Martin wrote:
> 
>> in my case it is always the slower ring that fails (the 100MB
>> network). Does rrp_mode passive expect both rings to have the same
>> speed?
>> 
>> Sebastian, can you confirm that in your environment also the slower
>> ring fails?
> 
>  I can confirm that, but that might also be a coincidence, since we both
> use
>  the slower network for backup only, i.e. ring(1).
>  Maybe it's related to the backup ring and not to the speed.

Some observations ...

I normally run same-speed rings at 1Gb, but in diagnosing a problem with
what turns out to be a cheap network card, I had occasion recently
to drop the normally 1Gb primary ring to (*cough*) 10Mb.  In that
configuration I was seeing the aforementioned behavior on the primary
ring, especially during a heavy DRBD sync on the same interface (and
don't tell me that I shouldn't run DRBD on a 10Mb link; I know that
and it was special circumstances).

That configuration was (not surprisingly) very unstable and didn't
last.  While I'm waiting for my back-ordered replacement NICs to
arrive the primary ring has been increased to 100Mb and the DRBD
syncer rate configured to be drastically less.  It seems stable
enough at the moment, although a DRBD resync obviously takes a
lot longer.

Devin