Hello, On Tue, 16 Dec 2014 08:58:23 -0700 Bryson McCutcheon wrote:
> Hey there, > > Is there a good work around if our SSDs are not handling D_SYNC very > well? We invested a ton of money into Samsung 840 EVOS and they are not > playing well with D_SYNC. Would really appreciate the help! > Baring any reply from the developers, I'm pretty sure the answer is no, as D_SYNC is a vital part of the journaling process. You _may_ get away with a hardware cache RAID controller (some models/makers will use that cache in JBOD mode, too). And while I very much can sympathize with you (I have dozens of new Toshiba DTxx drives sitting on a pile that perform quite nicely for a week before they go into half to 10% speed mode for at least 10 hours) and don't want to sound snarky, penultimately you get what you pay for. Journals on consumer SSDs are a bad idea. Aside form the performance issues you're experiencing, Samsung doesn't really give a TBW value for them, the estimation based on their claims is about 100TBW for the 120GB model. While not bad, it's something I'd be weary about with regards to long term usage. http://ssdendurancetest.com/ssd-endurance-test-report/Samsung-840-EVO-120 The only reliable game in town at this point in time are Intel DC S3700 models, the 200GB model for example has a TBW of 1.8PB and will keep its speed w/o the need for TRIM or massive underprovisioning. Christian -- Christian Balzer Network/Systems Engineer ch...@gol.com Global OnLine Japan/Fusion Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
