you can find in http://ceph.com/pgcalc/ 2016-03-15 23:41 GMT+08:00 Martin Palma <martin@xxxxxxxx>: > Hi all, > > The documentation [0] gives us the following formula for calculating > the number of PG if the cluster is bigger than 50 OSDs: > > (OSDs * 100) > Total PGs = ------------ > pool size > > When we have mixed storage server (HDD disks and SSD disks) and we > have defined different roots in our crush map to map some pools only > to HDD disk and some to SSD disks like described by Sebastien Han [1]. > > In the above formula what number of OSDs should be use to calculate > the PGs for a pool only on the HDD disks? The total number of OSDs in > a cluster or only the number of OSDs which have an HDD disk as > backend? > > Best, > Martin > > > [0] http://docs.ceph.com/docs/master/rados/operations/placement-groups/#choosing-the-number-of-placement-groups > [1] http://www.sebastien-han.fr/blog/2014/08/25/ceph-mix-sata-and-ssd-within-the-same-box/ > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- thanks huangjun _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com