On Mon, 5 Nov 2012, Josh Durgin wrote: > On 11/04/2012 03:42 AM, Sage Weil wrote: > > The wip-explicit-pgnum changes the 'ceph osd pool create <name> <pgnum>' > > command to require the pg_num value instead of defaulting to 8. This > > would make it harder for users to get this wrong. > > I like this. It'd be great if we could add a pgnum argument to > 'rados mkpool' and the corresponding librados pool_create* functions > too. I'm tempted to remove those commands from teh rados tool. I think we need to keep them in the librados api, tho, so maybe that's not helpful. Anyway, yeah, definitely! > > On the other hand, it probably also breaks some scripts for deploying > > OpenStack that create volume and image pools. :/ > > If those scripts are creating pools with 8 pgs, they're going to > create problems anyway. I don't mind breaking them as long as it's well > documented (i.e. release notes and docs on 'ceph osd pool create' > should mention the change). Ok. Let's try to do this this week for bobtail! sage > > > Ideas? > > > > The original idea was that the monitor would automagically notice when a > > small pgnum pool gets lots of objects and trigger a split. Even if we > > don't do that, pretty soon now you'll be able to explicitly increase > > pg_num. I still think it might be a good idea to require it up-front, > > though. > > Until split is implemented and well-tested, I think it makes sense to > require it up-front. It's easy to relax that requirement later if we > want to make it more automatic. > > > An alternative would be to default to a larger number (say, num_osds << > > 2). My concern there is that it makes it easy to create lots of pgs for > > pools that may be small, and it's still not large enough to get good > > performance for the "create pool, run rados bench" crowd. > > It would also be easy to create too few pgs, and then add a bunch of > osds later. > > Josh > -- > 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
