Thanks for the info. On Thu, Sep 6, 2018 at 7:03 PM Darius Kasparavičius <daz...@gmail.com> wrote:
> Hello, > > I'm currently running a similar setup. It's running a blustore OSD > with 1 NVME device for db/wal devices. That NVME device is not large > enough to support 160GB db partition per osd, so I'm stuck with 50GB > each. Currently haven't had any issues with slowdowns or crashes. > > The cluster is relatively idle. Up to 10k iops at peaks with 50/50 > read/write io distribution. Thought throughput is a different matter > It's more like 10:1 with 1GBps/100MBps. > > I have noticed that the best latencies I can get from using raid0 on > sas devices is running them in Writeback and disabled readahead on > controler. It might be that you will have different results. I wish > you luck in testing it. > > > On Thu, Sep 6, 2018 at 4:14 PM David Turner <drakonst...@gmail.com> wrote: > > > > The official ceph documentation recommendations for a db partition for a > 4TB bluestore osd would be 160GB each. > > > > Samsung Evo Pro is not an Enterprise class SSD. A quick search of the ML > will allow which SSDs people are using. > > > > As was already suggested, the better option is an HBA as opposed to a > raid controller. If you are set on your controllers, write-back is fine as > long as you have BBU. Otherwise you should be using write-through. > > > > On Thu, Sep 6, 2018, 8:54 AM Muhammad Junaid <junaid.fsd...@gmail.com> > wrote: > >> > >> Thanks. Can you please clarify, if we use any other enterprise class > SSD for journal, should we enable write-back caching available on raid > controller for journal device or connect it as write through. Regards. > >> > >> On Thu, Sep 6, 2018 at 4:50 PM Marc Roos <m.r...@f1-outsourcing.eu> > wrote: > >>> > >>> > >>> > >>> > >>> Do not use Samsung 850 PRO for journal > >>> Just use LSI logic HBA (eg. SAS2308) > >>> > >>> > >>> -----Original Message----- > >>> From: Muhammad Junaid [mailto:junaid.fsd...@gmail.com] > >>> Sent: donderdag 6 september 2018 13:18 > >>> To: ceph-users@lists.ceph.com > >>> Subject: [ceph-users] help needed > >>> > >>> Hi there > >>> > >>> Hope, every one will be fine. I need an urgent help in ceph cluster > >>> design. We are planning 3 OSD node cluster in the beginning. Details > are > >>> as under: > >>> > >>> Servers: 3 * DELL R720xd > >>> OS Drives: 2 2.5" SSD > >>> OSD Drives: 10 3.5" SAS 7200rpm 3/4 TB > >>> Journal Drives: 2 SSD's Samsung 850 PRO 256GB each Raid controller: > PERC > >>> H710 (512MB Cache) OSD Drives: On raid0 mode Journal Drives: JBOD Mode > >>> Rocks db: On same Journal drives > >>> > >>> My question is: is this setup good for a start? And critical question > >>> is: should we enable write back caching on controller for Journal > >>> drives? Pls suggest. Thanks in advance. Regards. > >>> > >>> Muhammad Junaid > >>> > >>> > >>> > >> _______________________________________________ > >> 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 >
_______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
