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 chibi@xxxxxxx Global OnLine Japan/Rakuten Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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