Re: [ceph-users] Increasing pg_num

2016-05-16 Thread Christian Balzer
Hello, On Tue, 17 May 2016 12:12:02 +1000 Chris Dunlop wrote: > Hi Christian, > > On Tue, May 17, 2016 at 10:41:52AM +0900, Christian Balzer wrote: > > On Tue, 17 May 2016 10:47:15 +1000 Chris Dunlop wrote: > > Most your questions would be easily answered if you did spend a few > > minutes with

Re: [ceph-users] Increasing pg_num

2016-05-16 Thread Chris Dunlop
Hi Christian, On Tue, May 17, 2016 at 10:41:52AM +0900, Christian Balzer wrote: > On Tue, 17 May 2016 10:47:15 +1000 Chris Dunlop wrote: > Most your questions would be easily answered if you did spend a few > minutes with even the crappiest test cluster and observing things (with > atop and the li

Re: [ceph-users] Increasing pg_num

2016-05-16 Thread Christian Balzer
Hello, On Tue, 17 May 2016 10:47:15 +1000 Chris Dunlop wrote: > On Tue, May 17, 2016 at 08:21:48AM +0900, Christian Balzer wrote: > > On Mon, 16 May 2016 22:40:47 +0200 (CEST) Wido den Hollander wrote: > > > > > > pg_num is the actual amount of PGs. This you can increase without any > > > actua

Re: [ceph-users] Increasing pg_num

2016-05-16 Thread Chris Dunlop
On Mon, May 16, 2016 at 10:40:47PM +0200, Wido den Hollander wrote: > > Op 16 mei 2016 om 7:56 schreef Chris Dunlop : > > Why do we have both pg_num and pgp_num? Given the docs say "The pgp_num > > should be equal to the pg_num": under what circumstances might you want > > these different, apart fr

Re: [ceph-users] Increasing pg_num

2016-05-16 Thread Chris Dunlop
On Tue, May 17, 2016 at 08:21:48AM +0900, Christian Balzer wrote: > On Mon, 16 May 2016 22:40:47 +0200 (CEST) Wido den Hollander wrote: > > > > pg_num is the actual amount of PGs. This you can increase without any > > actual data moving. > > Yes and no. > > Increasing the pg_num will split PGs, w

Re: [ceph-users] Increasing pg_num

2016-05-16 Thread Christian Balzer
Hello, On Mon, 16 May 2016 22:40:47 +0200 (CEST) Wido den Hollander wrote: > > > Op 16 mei 2016 om 7:56 schreef Chris Dunlop : > > > > > > Hi, > > > > I'm trying to understand the potential impact on an active cluster of > > increasing pg_num/pgp_num. > > > > The conventional wisdom, as gle

Re: [ceph-users] Increasing pg_num

2016-05-16 Thread Wido den Hollander
> Op 16 mei 2016 om 7:56 schreef Chris Dunlop : > > > Hi, > > I'm trying to understand the potential impact on an active cluster of > increasing pg_num/pgp_num. > > The conventional wisdom, as gleaned from the mailing lists and general > google fu, seems to be to increase pg_num followed by pg