Maybe because of this 850 evo / 850 pro listed here as 1.9MB/s 1.5MB/s http://www.sebastien-han.fr/blog/2014/10/10/ceph-how-to-test-if-your-ssd-is-suitable-as-a-journal-device/ -----Original Message----- From: Rafał Wądołowski [mailto:rwadolowski@xxxxxxxxxxxxxx] Sent: donderdag 4 januari 2018 16:56 To: ceph@xxxxxxxxxx; ceph-users@xxxxxxxxxxxxxx Subject: Re: Performance issues on Luminous I have size of 2. We know about this risk and we accept it, but we still don't know why performance so so bad. Cheers, Rafał Wądołowski On 04.01.2018 16:51, ceph@xxxxxxxxxx wrote: I assume you have size of 3 then divide your expected 400 with 3 and you are not far Away from what you get... In Addition you should Never use Consumer grade ssds for ceph as they will be reach the DWPD very soon... Am 4. Januar 2018 09:54:55 MEZ schrieb "Rafał Wądołowski" <rwadolowski@xxxxxxxxxxxxxx> <mailto:rwadolowski@xxxxxxxxxxxxxx> : Hi folks, I am currently benchmarking my cluster for an performance issue and I have no idea, what is going on. I am using these devices in qemu. Ceph version 12.2.2 Infrastructure: 3 x Ceph-mon 11 x Ceph-osd Ceph-osd has 22x1TB Samsung SSD 850 EVO 1TB 96GB RAM 2x E5-2650 v4 4x10G Network (2 seperate bounds for cluster and public) with MTU 9000 I had tested it with rados bench: # rados bench -p rbdbench 30 write -t 1 Total time run: 30.055677 Total writes made: 1199 Write size: 4194304 Object size: 4194304 Bandwidth (MB/sec): 159.571 Stddev Bandwidth: 6.83601 Max bandwidth (MB/sec): 168 Min bandwidth (MB/sec): 140 Average IOPS: 39 Stddev IOPS: 1 Max IOPS: 42 Min IOPS: 35 Average Latency(s): 0.0250656 Stddev Latency(s): 0.00321545 Max latency(s): 0.0471699 Min latency(s): 0.0206325 # ceph tell osd.0 bench { "bytes_written": 1073741824, "blocksize": 4194304, "bytes_per_sec": 414199397 } Testing osd directly # dd if=/dev/zero of=/dev/sdc bs=4M oflag=direct count=100 100+0 records in 100+0 records out 419430400 bytes (419 MB, 400 MiB) copied, 1.0066 s, 417 MB/s When I do dd inside vm (bs=4M wih direct), I have result like in rados bench. I think that the speed should be arround ~400MB/s. Is there any new parameters for rbd in luminous? Maybe I forgot about some performance tricks? If more information needed feel free to ask. _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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