On Tue, 19 Jun 2012, Stefan Priebe - Profihost AG wrote: > Am 19.06.2012 15:01, schrieb Mark Nelson: > > On 06/19/2012 01:32 AM, Stefan Priebe - Profihost AG wrote: > > > Am 19.06.2012 06:41, schrieb Alexandre DERUMIER: > > > > Hi Stephann > > > > recommandations are 30-50 PGS by osd if I remember. > > > > > > > rbd, data and metadata have 2176 PGs with 12 OSD. This is 181,333333333 > > > per OSD?! > > > > > > Stefan > > > > That's probably fine, it just means that you will have a better > > pseudo-random distribution of OSD combinations (It does have higher > > cpu/memory overhead though). Figuring out how many PGs you should have > > per OSD depends on a lot of factors including how many OSDs you have, > > how many nodes, CPU, memory, etc. I'm guessing ~180 per OSD won't cause > > problems. On the other hand, with low OSD counts you could probably have > > fewer and be fine too. > > But this number 2176 of PGs were set while doing mkcephfs - how is it > calculated? num_pgs = num_osds << osd_pg_bits which is configurable via --osd-pg-bits N or ceph.conf (at mkcephfs time). The default is 6. sage -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
