[ceph-users] Re: kvm vm cephfs mount hangs on osd node (something like umount -l available?) (help wanted going to production)

I really would like to use the hosts because they have each 16c/32t and an average load of just 2-3.

Hi Eugen, Indeed some really useful tips explaining what goes wrong, yet this thread[1] is about cephfs directly mounted on the osd node. I was having this also quite some time without any problems until suddenly I ran into the same issue as they had. I think I did not have any issues with the kernel client cephfs mount with luminous until I enabled the cephfs snapshots. Then I had to switch to the fuse client. In my case I am running a vm on the the osd node, which I thought would be different. I have been able to reproduce this stale mount just 2 times now. I have been testing with 10x more clients and it still works. Anyway I decided to move everything to rbd. I have been running vm's with rbd images without problems colocated on osd nodes for quite some time. I really would like to use the hosts because they have each 16c/32t and an average load of just 2-3. Unfortunately I did not document precisely how I recovered from the stale mount. I would like to see if I can reduce the amount of steps to take. Things started happening for me after I did the mds failover. Then I got blocked clients that I could unblock and fix the mount with mount -l Thanks for the pointers, I have linked them in my docs ;) -----Original Message----- To: ceph-users(a)ceph.io Subject: [ceph-users] Re: kvm vm cephfs mount hangs on osd node (something like umount -l available?) (help wanted going to production) Hi, there have been several threads about hanging cephfs mounts, one quite long thread [1] describes a couple of debugging options but also mentions to avoid mounting cephfs on OSD nodes in a production environment. Do you see blacklisted clients with 'ceph osd blacklist ls'? If the answer is yes try to unblock that client [2]. The same option ('umount -l') is available on a cephfs client, you can try that, too. Other options described in [1] are to execute an MDS failover, but sometimes a reboot of that VM is the only solution left. Regards, Eugen [1] http://lists.ceph.com/pipermail/ceph-users-ceph.com/2018-August/028719.html [2] https://docs.ceph.com/en/latest/cephfs/eviction/#advanced-un-blocklisting-a… Zitat von Marc Roos <M.Roos(a)f1-outsourcing.eu>eu>: _______________________________________________ ceph-users mailing list -- ceph-users(a)ceph.io To unsubscribe send an email to ceph-users-leave(a)ceph.io