On Wed, Aug 12, 2015 at 5:08 AM, Bob Ababurko <bob@xxxxxxxxxxxx> wrote: > What is risky about enabling mds_bal_frag on a cluster with data and will > there be any performance degradation if enabled? No specific gotchas, just that it is not something that has especially good coverage in our automated tests. We recently enabled it for our general purpose tests (i.e. not specifically exercising fragmentation, just normal fs workloads) and nothing's blown up horribly, but that's about as far as the assurance goes. Performance wise, there's a cost associated with splitting things up and merging them, but a benefit associated with having smaller fragments in general. Probably doesn't make a huge difference outside of the initial part where your existing large directories would all be getting fragmented all of a sudden. John _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com