On Thu, Aug 6, 2015 at 1:55 PM, Hector Martin <hector@xxxxxxxxxxxxxx> wrote: > On 2015-08-06 17:18, Wido den Hollander wrote: >> >> The mount of PGs is cluster wide and not per pool. So if you have 48 >> OSDs the rule of thumb is: 48 * 100 / 3 = 1600 PGs cluster wide. >> >> Now, with enough memory you can easily have 100 PGs per OSD, but keep in >> mind that the PG count is cluster-wide and not per pool. > > > I understand that now, but that is not what the docs say. The docs say 4096 > PGs per pool (i.e. in the "ceph osd pool create" command) for 48 OSDs. Which > seems to be off by a factor of 2.5x from the actual do-the-math > recommendation for one 3x pool, and successively larger factors as you add > pools. > 4096 was the count considering *all* pools in mind.. since you have 4 pools you should consider reducing the number. Also follow the rule Wido said in the earlier mail for calculation ie n_OSD*100/3 . BTW http://ceph.com/pgcalc/ might help you in selecting this number better. ______ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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