Do not use consumer SSD for OSD. Especially for journal disk. If you use consumer SSD, please consider add some dedicated SSD Enterprise for journal disk. Ratio should be 1:2 or 1:4 (1 SSD Enterprise with 4 SSD Consumer).
Best Regards, On Fri, Jan 5, 2018 at 3:20 PM, Marc Roos <m.r...@f1-outsourcing.eu> wrote: > > > 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:rwadolow...@cloudferro.com] > Sent: donderdag 4 januari 2018 16:56 > To: c...@elchaka.de; ceph-users@lists.ceph.com > Subject: Re: [ceph-users] 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, c...@elchaka.de 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" > <rwadolow...@cloudferro.com> <mailto:rwadolow...@cloudferro.com> : > > 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@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > -- ============== Nghia Than
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