Hi, i had the 250 GB Samsung PRO. They suck for journals because they are super slow in the - for ceph - required dsync.
Have a look at https://www.sebastien-han.fr/blog/2014/10/10/ceph-how-to-test-if-your-ssd-is-suitable-as-a-journal-device/ for more informations. I advice you also to drop this 1 TB desktop SSD's. All this kind of SSD's can usually not provide reliable IOPS. They can peak a lot for a short amount of time, but then they die away under pressure ( even below 7200 RPM rotating hdd's ). Good luck with your testing ! -- Mit freundlichen Gruessen / Best regards Oliver Dzombic IP-Interactive mailto:i...@ip-interactive.de Anschrift: IP Interactive UG ( haftungsbeschraenkt ) Zum Sonnenberg 1-3 63571 Gelnhausen HRB 93402 beim Amtsgericht Hanau Geschäftsführung: Oliver Dzombic Steuer Nr.: 35 236 3622 1 UST ID: DE274086107 Am 24.05.2016 um 20:20 schrieb Max A. Krasilnikov: > Hello! > > I have cluster with 5 SSD drives as OSD backed by SSD journals, one per osd. > One > osd per node. > > Data drives is Samsung 850 EVO 1TB, journals are Samsung 850 EVO 250G, journal > partition is 24GB, data partition is 790GB. OSD nodes connected by 2x10Gbps > linux bonding for data/cluster network. > > When doing random write with 4k blocks with direct=1, buffered=0, > iodepth=32..1024, ioengine=libaio from nova qemu virthost I can get no more > than > 9kiops. Randread is about 13-15 kiops. > > Trouble is that randwrite not depends on iodepth. read, write can be up to > 140kiops, randread up to 15 kiops. randwrite is always 2-9 kiops. > > Ceph cluster is mixed of jewel and hammer, upgrading now to jewel. On Hammer I > got the same results. > > All journals can do up to 32kiops with the same config for fio. > > I am confused because EMC ScaleIO can do much more iops what is boring my boss > :) > _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
