Le 23/12/2015 16:18, Mart van Santen a écrit : > Hi all, > > > On 12/22/2015 01:55 PM, Wido den Hollander wrote: >> On 22-12-15 13:43, Andrei Mikhailovsky wrote: >>> Hello guys, >>> >>> Was wondering if anyone has done testing on Samsung PM863 120 GB version to see how it performs? IMHO the 480GB version seems like a waste for the journal as you only need to have a small disk size to fit 3-4 osd journals. Unless you get a far greater durability. >>> >> In that case I would look at the SM836 from Samsung. They are sold as >> write-intensive SSDs. >> >> Wido >> > > Today I received a small batch of SM863 (1.9TBs) disks. So maybe these > testresults are helpfull for making a decision > This is on an IBM X3550M4 with a MegaRaid SAS card (so not in jbod > mode). Unfortunally I have no suitable JBOD card available at my test > server so I'm stuck with the "RAID" layer in the HBA > > > > disabled drive cache, disabled controller cache > --------------------------------------------------------------- > > > 1 job > ----------- > Run status group 0 (all jobs): > WRITE: io=906536KB, aggrb=15108KB/s, minb=15108KB/s, maxb=15108KB/s, > mint=60001msec, maxt=60001msec > > Disk stats (read/write): > sdd: ios=91/452978, merge=0/0, ticks=12/39032, in_queue=39016, util=65.04% Either the MegaRaid SAS card is the bottleneck or SM863 1.9TB are 8x slower than PM863 480GB on this particular test which is a bit surprising: it would make the SM863 one of the slowest (or even the slowest) DC SSD usable as Ceph journals. Do you have any other SSD (if possible one of the models or one similar to the ones listed on http://www.sebastien-han.fr/blog/2014/10/10/ceph-how-to-test-if-your-ssd-is-suitable-as-a-journal-device/ which give more than 15MB/s with one job) connected to the same card model you could test for comparison? Lionel _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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