> In the past we've hit some performance issues with RBD cache that we've > fixed, but we've never really tried pushing a single VM beyond 40+K read > IOPS in testing (or at least I never have). I suspect there's a couple > of possibilities as to why it might be slower, but perhaps joshd can > chime in as he's more familiar with what that code looks like. >
At high queue-depths and high IOPS, I would suspect that the bottleneck is the single, coarse-grained mutex protecting the cache data structures. It's been a back burner item to refactor the current cache mutex into finer-grained locks. Jason _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
