On Tue, Apr 14, 2015 at 1:18 PM, Francois Lafont <flafdivers@xxxxxxx> wrote: > Robert LeBlanc wrote: > >> Hmmm....I've been deleting the OSD (ceph osd rm X; ceph osd crush rm osd.X) >> along with removing the auth key. This has caused data movement, > > Maybe but if the flag "noout" is set, removing an OSD of the cluster doesn't > trigger at all data movement (I have tested with Firefly). > >> I'd still like to know the difference between norecover and nobackfill if >> anyone knows. > > If I read this page, http://ceph.com/docs/master/rados/operations/pg-states/, > I understand that backfilling is just a special case of recovery more "detailed" > (but I'm not a ceph expert). norecover and nobackfill pause the OSD threadpools that do recovery and backfill. So if an OSD restarts or something, this prevents it from doing any of the work to come up to date. If that sounds like a really bad thing, you're right: don't use them. They're really only intended for situations where the PG recovery itself is causing the cluster to be less available, so if everything is overloaded you can set these values alongside the more generally-useful nodown/noout flags and let things catch up before removing them. -Greg _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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