Hi Irek, I am using v0.80.5 Firefly <http://ceph.com/docs/master/release-notes/#v0-80-5-firefly> -sumit
On Fri, Feb 13, 2015 at 1:30 PM, Irek Fasikhov <malm...@gmail.com> wrote: > Hi. > What version? > > 2015-02-13 6:04 GMT+03:00 Sumit Gaur <sumitkg...@gmail.com>: > >> Hi Chir, >> Please fidn my answer below in blue >> >> On Thu, Feb 12, 2015 at 12:42 PM, Chris Hoy Poy <ch...@gopc.net> wrote: >> >>> Hi Sumit, >>> >>> A couple questions: >>> >>> What brand/model SSD? >>> >> samsung 480G SSD(PM853T) having random write 90K IOPS (4K, 368MBps) >> >>> >>> What brand/model HDD? >>> >> 64GB memory, 300GB SAS HDD (seagate), 10Gb nic >> >>> >>> Also how they are connected to controller/motherboard? Are they sharing >>> a bus (ie SATA expander)? >>> >> no , They are connected with local Bus not the SATA expander. >> >> >>> >>> RAM? >>> >> *64GB * >> >>> >>> Also look at the output of "iostat -x" or similiar, are the SSDs >>> hitting 100% utilisation? >>> >> *No, SSD was hitting 2000 iops only. * >> >>> >>> I suspect that the 5:1 ratio of HDDs to SDDs is not ideal, you now have >>> 5x the write IO trying to fit into a single SSD. >>> >> * I have not seen any documented reference to calculate the ratio. Could >> you suggest one. Here I want to mention that results for 1024K write >> improve a lot. Problem is with 1024K read and 4k write .* >> >> *SSD journal 810 IOPS and 810MBps* >> *HDD journal 620 IOPS and 620 MBps* >> >> >> >> >>> I'll take a punt on it being a SATA connected SSD (most common), 5x ~130 >>> megabytes/second gets very close to most SATA bus limits. If its a shared >>> BUS, you possibly hit that limit even earlier (since all that data is now >>> being written twice out over the bus). >>> >>> cheers; >>> \Chris >>> >>> >>> ------------------------------ >>> *From: *"Sumit Gaur" <sumitkg...@gmail.com> >>> *To: *ceph-users@lists.ceph.com >>> *Sent: *Thursday, 12 February, 2015 9:23:35 AM >>> *Subject: *[ceph-users] ceph Performance with SSD journal >>> >>> >>> Hi Ceph-Experts, >>> >>> Have a small ceph architecture related question >>> >>> As blogs and documents suggest that ceph perform much better if we use >>> journal on SSD. >>> >>> I have made the ceph cluster with 30 HDD + 6 SSD for 6 OSD nodes. 5 HDD >>> + 1 SSD on each node and each SSD have 5 partition for journaling 5 OSDs >>> on the node. >>> >>> Now I ran similar test as I ran for all HDD setup. >>> >>> What I saw below two reading goes in wrong direction as expected >>> >>> 1) 4K write IOPS are less for SSD setup, though not major difference >>> but less. >>> 2) 1024K Read IOPS are less for SSD setup than HDD setup. >>> >>> On the other hand 4K read and 1024K write both have much better numbers >>> for SSD setup. >>> >>> Let me know if I am missing some obvious concept. >>> >>> Thanks >>> sumit >>> >>> _______________________________________________ >>> 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 >> >> > > > -- > С уважением, Фасихов Ирек Нургаязович > Моб.: +79229045757 >
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