> -----Original Message----- > From: Stefan Priebe [mailto:s.priebe@xxxxxxxxxxxx] > Sent: Donnerstag, 02. Jänner 2014 18:36 > To: Dietmar Maurer; Dino Yancey > Cc: ceph-users@xxxxxxxxxxxxxx > Subject: Re: rados benchmark question > > Hi, > > Am 02.01.2014 17:10, schrieb Dietmar Maurer: > >> Having your journals on the same disk causes all data to be written twice, i.e. > >> once to the journal and once to the > >> osd store. Notice that your tested throughput is slightly more than > >> half your expected maximum... > > > > But AFAIK OSD bench already considers journal writes. The disk can > > write about 100MB/s, so 55MB/s is already half speed! > > > > So that does not explain the behavior for me. > > Can you please post > > iostat -x 5 (for about 30 seconds) Note: sdb and sdc are my OSDs: # iostat -x 5 (after about 30 seconds) Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sdb 0.00 3.80 0.00 187.40 0.00 84663.60 903.56 157.62 796.93 0.00 796.93 5.34 100.00 sdc 0.00 30.00 0.00 169.60 0.00 72501.80 854.97 47.33 279.14 0.00 279.14 5.58 94.62 _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |