> On 26/03/2015, at 22.53, Steffen W Sørensen <[email protected]> wrote: > >> >> On 26/03/2015, at 21.07, J-P Methot <[email protected] >> <mailto:[email protected]>> wrote: >> >> That's a great idea. I know I can setup cinder (the openstack volume >> manager) as a multi-backend manager and migrate from one backend to the >> other, each backend linking to different pools of the same ceph cluster. >> What bugs me though is that I'm pretty sure the image store, glance, >> wouldn't let me do that. Additionally, since the compute component also has >> its own ceph pool, I'm pretty sure it won't let me migrate the data through >> openstack. > Hm wouldn’t it be possible to do something similar ala: > > # list object from src pool > rados ls objects loop | filter-obj-id | while read obj; do > # export $obj to local disk > rados -p pool-wth-too-many-pgs get $obj > # import $obj from local disk to new pool > rados -p better-sized-pool put $obj > done and of course when done redirect glance to new pool :)
Not sure, but this might require you to quenching the object usage from openstack during migration, dunno, maybe ask openstack community if it’s possible to live migration of objects first :/ > > possible split/partition list of objects into multiple concurrent loops, > possible from multiple boxes as seems fit for resources at hand, cpu, memory, > network, ceph perf. > > /Steffen > >> >> >> >> On 3/26/2015 3:54 PM, Steffen W Sørensen wrote: >>>> On 26/03/2015, at 20.38, J-P Methot <[email protected]> wrote: >>>> >>>> Lately I've been going back to work on one of my first ceph setup and now >>>> I see that I have created way too many placement groups for the pools on >>>> that setup (about 10 000 too many). I believe this may impact performances >>>> negatively, as the performances on this ceph cluster are abysmal. Since it >>>> is not possible to reduce the number of PGs in a pool, I was thinking of >>>> creating new pools with a smaller number of PGs, moving the data from the >>>> old pools to the new pools and then deleting the old pools. >>>> >>>> I haven't seen any command to copy objects from one pool to another. Would >>>> that be possible? I'm using ceph for block storage with openstack, so >>>> surely there must be a way to move block devices from a pool to another, >>>> right? >>> What I did a one point was going one layer higher in my storage >>> abstraction, and created new Ceph pools and used those for new storage >>> resources/pool in my VM env. (ProxMox) on top of Ceph RBD and then did a >>> live migration of virtual disks there, assume you could do the same in >>> OpenStack. >>> >>> My 0.02$ >>> >>> /Steffen >> >> >> -- >> ====================== >> Jean-Philippe Méthot >> Administrateur système / System administrator >> GloboTech Communications >> Phone: 1-514-907-0050 >> Toll Free: 1-(888)-GTCOMM1 >> Fax: 1-(514)-907-0750 >> [email protected] >> http://www.gtcomm.net >> > > _______________________________________________ > ceph-users mailing list > [email protected] <mailto:[email protected]> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > <http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com>
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