[sheepdog-users] vdi stalled with 2 out of 3 node online

[richter at ecos.de]

> > last Friday one of my three nodes has left the cluster (I don't have
> > any idea why). A "dog node recovery" shows "Waiting for other nodes to
> > join cluster".
> 
> I guess you are using corosync, which is said to be easily running into
network
> partition problem.
> 

Yes, I am using corosync. It might be the case that corosync had a problem,
but at the time the VM stalled, corosync was in sync and sheep wasn't able
to rejoin the cluster. I had to restart sheep (and only sheep) to rejoin the
cluster. I would exptect that sheep rejoins the cluster as soon as corosync
is in sync again and as far as I can tell this was the case in the past
(that was with 0.7.x).


> >
> > If I a have a cluster with three node and number of copies is set to
> > three, why does a VM stop working, if two nodes up and running?
> > Moreover, it is strange that it stopped after three days.
> >
> 
> If you don't add '-t' for 'dog cluster format', sheepdog cluster will run
without
> any problem even if your nodes number < redundancy number.
> 

I do not have used -t during format. So it should work, but it didn't work.
To be precise, it worked for 3 days without problems, but then it suddenly
stopped (there was heavy I/O in the VM during this time). Maybe it's again a
corner case in the local cache, like I reported it before for other
situations, but this time even restarting the VM didn't change anything. It
worked again, when the third node rejoined the cluster.

Regards

Gerald