Hello, On Tue, 28 Jun 2016 18:23:02 +0300 George Shuklin wrote:
> Hello. > > I'm testing different configuration for Ceph. What version... > I found that osd are > REALLY hungry for cpu. > They can be, but unlikely in your case. > I've created a tiny pool with size 1 with single OSD made of fast intel > SSD (2500-series), on old dell server (R210), Xeon E3-1230 V2 @ 3.30GHz. > At a replication size of 1, a totally unrealistic test scenario. Ignoring that, an Intel SSD PRO 2500 is a consumer SSD and as such with near certainty ill suited for usage with Ceph, especially when it comes to journals. Check/google the countless threads about what constitutes SSDs suitable for Ceph usage. > And when I benchmark it How? Fio, we can gather, but whether against a RBD image, with user or kernel client, with the fio RBD engine... >I see some horribly-low performance and clear > bottleneck at ceph-osd process: it consumes about 110% of CPU and giving 110% actual CPU usage? I'd wager a significant amount of that is IOWAIT... > me following results: 127 iops in fio benchmark (4k randwrite) for rbd > device, rados benchmark gives me ~21 IOPS and 76Mb/s (write). > Pretty clear indication that the SSD isn't handling sync writes well, lacking further info. > It this a normal CPU utilization for osd daemon for such tiny > performance? > > Relevant part of the crush map: > Irrelevant in this context really. Christian -- Christian Balzer Network/Systems Engineer ch...@gol.com Global OnLine Japan/Rakuten Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
