Thanks Greg, makes sense. Our ceph cluster currently has 16 OSDs, each with an 8TB disk. Sounds like 32 PGs at 3x replication might be a reasonable starting point? Thanks, -- Dan > On Nov 8, 2016, at 14:02, Gregory Farnum <gfarnum@xxxxxxxxxx> wrote: > > On Tue, Nov 8, 2016 at 9:37 AM, Dan Jakubiec <dan.jakubiec@xxxxxxxxx> wrote: >> Hello, >> >> Picking the number of PGs for the CephFS data pool seems straightforward, but how does one do this for the metadata pool? >> >> Any rules of thumb or recommendations? > > I don't think we have any good ones yet. You've got to worry about the > log and about the backing directory objects; depending on how your map > looks I'd just try and get enough for a decent IO distribution across > the disks you're actually using. Given the much lower amount of > absolute data you're less worried about balancing the data precisely > evenly and more concerned about not accidentally driving all IO to one > of 7 disks because you have 8 PGs, and all your supposedly-parallel > ops are contending. ;) > -Greg > >> >> Thanks, >> >> -- Dan Jakubiec >> _______________________________________________ >> 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
 |