Hi Christian, Thnx for your reply.
Case: CSE-825TQC-600LPB I made a typo with the CPU, it's a E3-1240 v5 3.5Ghz. So a E5-2620 v4 is recommended when i want to add SSD for caching ? With a caching tier, is the data on the caching tier a copy from data on the normal tier ? Is a caching tier with one SSD recommended or should i always have two SSD in replicated mode ? Kind regards, Tom On Mon, Aug 1, 2016 at 2:00 PM, Christian Balzer <[email protected]> wrote: > > Hello, > > On Mon, 1 Aug 2016 11:09:00 +0200 Tom T wrote: > > > Hi Ceph users > > > > We are planning to setup a small ceph cluster, starting with 3 nodes for > > VM's. > > I have some question about CPU and caching > > > > We would like to start with the following config: > > > > > > Supermicro X11SSI-LN4F > In which case? > > > Intel E3-1246 v3 3.5Ghz > A bit dated, but fast enough. > > > 32GB RAM > While enough for 4 OSDs, don't skimp on RAM if you can afford, reads will > thank you for it. > > > S3500 80GB M.2 for OS > If you're short on money, maybe use a 535 (or 2!) for that purpose. > > > AOC-S3008L-L8e (LSI SAS3008) > > 4x 2TB ST2000NM0034 SAS12Gb > > I fail to see the need/point for 7.2k RPM HDDs with a mere 128MB of cache > hanging of a 12Gb/s bus, but maybe that's just me. > > > 1x Intel 200GB S3710 for journal (via onboard SATA) > Good enough. > > > 4x 1Gb for networking > > > Unless all your clients also are limited to GbE and you have no budget to > change that, don't. > > For VM's latency will be one of your biggest nemesis (nemesii?), use > faster (lower latency) networking. > > > Questions: > > Is the CPU enough ? > See above. > > > I would like to run the monitoring deamon on the same host, would this > be a > > problem ? > > > Just within the normal usage needs, more RAM in that case anyway. > > > Optionally i would like to add an extra SSD for caching > Not really recommended with that server and not particular helpful with > that network. > A single SSD of any caliber will/can eat one of your CPU cores by itself > and then ask for seconds. > > > Does write-back caching also optimize the reads ? > Yes, subject to "correct" configuration of course. > > > Do I need two SSD's per node > > > From a performance point of view, not so much. > Your network can't even saturate one 200GB DC S3710. > > From a redundancy point of view you might be better off with more nodes. > > Christian > > > > > Kind regards, > > Tom > > > -- > Christian Balzer Network/Systems Engineer > [email protected] Global OnLine Japan/Rakuten Communications > http://www.gol.com/ >
_______________________________________________ ceph-users mailing list [email protected] http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
