Ceph » CephFS

from ML:

On Fri, 15 Jun 2012, Amon Ott wrote:
> Hello all,
> 
> I have seen this for a long time, but never investigated further. After stabl$
> test runs for several days, this is our last known show stopper before using  
> Ceph in production. We are running 0.47.2 on 32 Bit.
> 
> If we restart MDS (or all ceph daemons) on all nodes, one after another or al$
> together, they first recover and then the active one starts to spin with full 
> cpu and does not answer any more. After a while, the next takes over, starts  
> to spin, etc., until the whole cluster is unusable. This is completely
> reproducable and happens even without any active client.
> 
> As ecpected, ceph -w shows lots of
> "2012-06-15 11:35:28.588775   mds e959: 1/1/1 up {0=3=up:active(laggy or
> crashed)}" 
> 
> It does not help to stop all services on all nodes for minutes or longer and
> to restart them - MDS will restart spinning. But: If we reboot the whole
> cluster, everything goes back to work.
> 
> Today's MDS log is available at
> https://download.m-privacy.de/homeuser-mds.0.log.gz
>
> Is this a known problem? It has been with us for a looong time now, but since
> rebooting used to help, we never tracked it down.