On Wed, Mar 25, 2015 at 10:36 AM, Jake Grimmett <j...@mrc-lmb.cam.ac.uk> wrote: > Dear All, > > Please forgive this post if it's naive, I'm trying to familiarise myself > with cephfs! > > I'm using Scientific Linux 6.6. with Ceph 0.87.1 > > My first steps with cephfs using a replicated pool worked OK. > > Now trying now to test cephfs via a replicated caching tier on top of an > erasure pool. I've created an erasure pool, cannot put it under the existing > replicated pool. > > My thoughts were to delete the existing cephfs, and start again, however I > cannot delete the existing cephfs: > > errors are as follows: > > [root@ceph1 ~]# ceph fs rm cephfs2 > Error EINVAL: all MDS daemons must be inactive before removing filesystem > > I've tried killing the ceph-mds process, but this does not prevent the above > error. > > I've also tried this, which also errors: > > [root@ceph1 ~]# ceph mds stop 0 > Error EBUSY: must decrease max_mds or else MDS will immediately reactivate
Right, so did you run "ceph mds set_max_mds 0" and then repeating the stop command? :) > > This also fail... > > [root@ceph1 ~]# ceph-deploy mds destroy > [ceph_deploy.conf][DEBUG ] found configuration file at: > /root/.cephdeploy.conf > [ceph_deploy.cli][INFO ] Invoked (1.5.21): /usr/bin/ceph-deploy mds destroy > [ceph_deploy.mds][ERROR ] subcommand destroy not implemented > > Am I doing the right thing in trying to wipe the original cephfs config > before attempting to use an erasure cold tier? Or can I just redefine the > cephfs? Yeah, unfortunately you need to recreate it if you want to try and use an EC pool with cache tiering, because CephFS knows what pools it expects data to belong to. Things are unlikely to behave correctly if you try and stick an EC pool under an existing one. :( Sounds like this is all just testing, which is good because the suitability of EC+cache is very dependent on how much hot data you have, etc...good luck! -Greg > > many thanks, > > Jake Grimmett > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
