Ceph » CephFS

Hello,
thank you for the reply.

no, unfortunately i am not able to reproduce the error using debug ms = 20(for MDS)...here is the log for MDS[[http://pastebin.com/neuJ3kfB]]

Luckily the MDS is not crashing anymore...atleast so far :)

But clients are still not able to mount...

thanks for the info...

Ok, so generally speaking, the only time you shoudl see fsid mismatches like that is if you have daemons from multiple clusters (or versions of the cluster) running and the client is getting confused. Make sure you kill off all your daemons and restart. (The fsid is randomly generated during mkcephfs, so you probably did mkcephfs, started things up, ran it again without stopping all daemons, and started some new daemons.)

Thank you for reverting back so quickly.

Well in my scenario, i just have one Ceph server running. And yes, every time we do a mkcephfs, a new fsid is getting generated, but the clients are some how storing the fsid values and are not able to update it for the next session. I just have a single cluster, so i avoid the problems of multiple fsid's being active at any instant of time. Is there a way to flush the client cache?

Actually what did u mean by "without stopping all daemons"?...can you please explain this a bit clearly, i failed to understand. Did you mean the mon and osd daemons?

More to it, i noticed that when the ceph server is started, it is quite stable on itself. But when a client tries to mount, either successfully or in vain, the probability of the MDS crashing, goes very high.

by the way,
you have assigned a target version as v0.39...but in the site i can find only the source for v0.37...
even if v0.39 is under development, where is v0.38?
Thank you.

Gokul Krishnan wrote:

by the way,
you have assigned a target version as v0.39...but in the site i can find only the source for v0.37...
even if v0.39 is under development, where is v0.38?
Thank you.

Oops, with all the travel it slipped my mind. Building 0.38 now.

Gokul Krishnan wrote:

Thank you for reverting back so quickly.

Well in my scenario, i just have one Ceph server running. And yes, every time we do a mkcephfs, a new fsid is getting generated, but the clients are some how storing the fsid values and are not able to update it for the next session. I just have a single cluster, so i avoid the problems of multiple fsid's being active at any instant of time. Is there a way to flush the client cache?

Oh.. are you stopping/restarting the clients? If you have a client mounting an old fs, and run a mkcephfs to replace the fs, the client will be thoroughly confused. You need to umount before mkcephfs, or if you didn't, restart the clients.

Actually what did u mean by "without stopping all daemons"?...can you please explain this a bit clearly, i failed to understand. Did you mean the mon and osd daemons?

More to it, i noticed that when the ceph server is started, it is quite stable on itself. But when a client tries to mount, either successfully or in vain, the probability of the MDS crashing, goes very high.

Yes I am stopping the clients and remounting...but if im doing a mkcephfs, i make sure to umount all the clients before stopping the Ceph daemons.
But yes I dont restart the clients...but I assume the Ceph server has been designed to handle this case (all clients un-mounted, server stopped, mkcephfs again (generating new fs), started Ceph daemons and trying to mount clients again with new fsid), aren't they?