On 19 May 2018 at 09:20, Scottix <scot...@gmail.com> wrote: > It would be nice to have an option to have all IO blocked if it hits a > degraded state until it recovers. Since you are unaware of other MDS state, > seems like that would be tough to do.
I agree this would be a nice knob to have from the perspective of having consistent (and easy to diagnose) client behaviour when such a situation occurs. However I don't think this is possible, if a client is working in a directory served via rank-0 MDS (whilst rank-1 has just gone down) it isn't going to know rank-0 is down until the MONs do. So to get the "all stop" you are talking about the client would then have to undo already committed IO(!), the only other option would be "pinging" all ranks on every metadata change, and that sounds horrible. Maybe this is a case where you'd be better off putting NFS in front of your CephFS? -- Cheers, ~Blairo _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
