On Wed, 6 Feb 2013, Chen, Xiaoxi wrote: > But can we change the pg_num of a pool when the pool contains data? If > yes, how to do this? This functionality is merged, but still a bit experimental. The incantation is ceph osd pool set <poolname> pg_num <numpgs> --allow-experimental-feature Please test, but be careful on clusters with real data. sage > > -----Original Message----- > From: ceph-devel-owner@xxxxxxxxxxxxxxx [mailto:ceph-devel-owner@xxxxxxxxxxxxxxx] On Behalf Of Sage Weil > Sent: 2013?2?6? 9:50 > To: Mandell Degerness > Cc: ceph-devel@xxxxxxxxxxxxxxx > Subject: Re: Increase number of pg in running system > > On Tue, 5 Feb 2013, Mandell Degerness wrote: > > I would like very much to specify pg_num and pgp_num for the default > > pools, but they are defaulting to 64 (no OSDs are defined in the > > config file). I have tried using the options indicated by Artem, but > > they didn't seem to have any effect on the data and rbd pools which > > are created by default. Is there something I am missing? > > Ah, I see. Specifying this is awkward. In [mon] or [global], > > osd pg bits = N > osd pgp bits = N > > where N is the the number of bits to shift 1 to the left. So for 1024 PGs, you'd do 10. (What it's actually doing is MIN(1, num_osds) << N. > The default N is 6, so you're probaby seeing 64 PGs per pool by default.) > > sage > > > > > > On Tue, Feb 5, 2013 at 6:40 AM, ArtemGr <artemciy@xxxxxxxxx> wrote: > > > Martin B Nielsen <martin <at> unity3d.com> writes: > > >> Hi, > > >> > > >> Looking at: > > >> http://ceph.com/docs/master/rados/operations/pools/ > > >> > > >> It has this description roughly in the middle: > > >> > > >> --------------- > > >> Important > > >> Increasing the number of placement groups in a pool after you > > >> create the pool is still an experimental feature in Bobtail (v > > >> 0.56). We recommend defining a reasonable number of placement > > >> groups and maintaining that number until Ceph?s placement group > > >> splitting and merging functionality matures. > > >> --------------- > > >> > > >> However, I cannot find any references how to do this? > > >> > > >> I'm asking since we have a test system with 10TB data with only the > > >> default 8 PG's created. > > > > > > Here's how I do it in ceph.conf: > > > > > > [osd] > > > ; Increase groups number in order to decrease scrub size > > > osd pool default pg num = 64 > > > osd pool default pgp num = 64 > > > > > > > > > -- > > > 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 > > -- > > 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 > > > > > -- > 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 > -- 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
