On Sat, Dec 27, 2014 at 4:31 PM, Lindsay Mathieson <lindsay.mathieson@xxxxxxxxx> wrote: > On Sat, 27 Dec 2014 04:59:51 PM you wrote: >> Power supply means bigger capex and less redundancy, as the emergency >> procedure in case of power failure is less deterministic than with >> controlled battery-backed cache. > > Yes, the whole auto shut-down procedure is rather more complex and fragile > for a UPS than a controller cache > >> Anyway XFS nobarrier >> does not bring enough performance boost to be enabled by my >> experience. > > It makes a non-trivial difference on my (admittedly slow) setup, with write > bandwidth going from 35 MB/s to 51 MB/s > Are you able to separate log with data in your setup and check the difference? If your devices are working strictly under their upper limits for bw/IOPS, separating meta and data bytes may help a lot, at least for synchronous clients. So, depending on type of your benchmark (sync/async/IOPS-/bandwidth-hungry) you may win something just for crossing journal and data between disks (and increase failure domain for a single disk as well :) ). _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |