On Fri, Feb 16, 2018 at 11:20 AM, Eugen Block <ebl...@nde.ag> wrote: > Hi Jason, > >> ... also forgot to mention "rbd export --export-format 2" / "rbd >> import --export-format 2" that will also deeply export/import all >> snapshots associated with an image and that feature is available in >> the Luminous release. > > > thanks for that information, this could be very valuable for us. I'll have > to test that intesively, but not before next week. > > But a first quick test brought up a couple of issues which I'll have to > re-check before bringing them up here. > > One issue is worth mentioning, though: After I exported (rbd export > --export-format ...) a glance image and imported it back to a different pool > (rbd import --export-format ...) its snapshot was copied, but not protected. > This prevented nova from cloning the base image and leaving that instance in > error state. Protecting the snapshot manually and launch another instance > enabled nova to clone the image successfully. > > Could this be worth a bug report or is it rather something I did wrong or > missed?
Definitely deserves a bug tracker ticket opened. Thanks. > I wish you all a nice weekend! > > Regards > Eugen > > > Zitat von Jason Dillaman <jdill...@redhat.com>: > >> On Fri, Feb 16, 2018 at 8:08 AM, Jason Dillaman <jdill...@redhat.com> >> wrote: >>> >>> On Fri, Feb 16, 2018 at 5:36 AM, Jens-U. Mozdzen <jmozd...@nde.ag> wrote: >>>> >>>> Dear list, hello Jason, >>>> >>>> you may have seen my message on the Ceph mailing list about RDB pool >>>> migration - it's a common subject that pools were created in a >>>> sub-optimum >>>> fashion and i. e. pgnum is (not yet) reducible, so we're looking into >>>> means >>>> to "clone" an RBD pool into a new pool within the same cluster >>>> (including >>>> snapshots). >>>> >>>> We had looked into creating a tool for this job, but soon noticed that >>>> we're >>>> duplicating basic functionality of rbd-mirror. So we tested the >>>> following, >>>> which worked out nicely: >>>> >>>> - create a test cluster (Ceph cluster plus an Openstack cluster using an >>>> RBD >>>> pool) and some Openstack instances >>>> >>>> - create a second Ceph test cluster >>>> >>>> - stop Openstack >>>> >>>> - use rbd-mirror to clone the RBD pool from the first to the second Ceph >>>> cluster (IOW aborting rbd-mirror once the initial coping was done) >>>> >>>> - recreate the RDB pool on the first cluster >>>> >>>> - use rbd-mirror to clone the mirrored pool back to the (newly created) >>>> pool >>>> on the first cluster >>>> >>>> - start Openstack and work with the (recreated) pool on the first >>>> cluster >>>> >>>> So using rbd-mirror, we could clone an RBD pool's content to a >>>> differently >>>> structured pool on the same cluster - by using an intermediate cluster. >>>> >>>> @Jason: Looking at the commit history for rbd-mirror, it seems you might >>>> be >>>> able to shed some light on this: Do you see an easy way to modify >>>> rbd-mirror >>>> in such a fashion that instead of mirroring to a pool on a different >>>> cluster >>>> (having the same pool name as the original), mirroring would be to a >>>> pool on >>>> the *same* cluster, (obviously having a pool different name)? >>>> >>>> From the "rbd cppool" perspective, a one-shot mode of operation would be >>>> fully sufficient - but looking at the code, I have not even been able to >>>> identify the spots where we might "cut away" the networking part, so >>>> that >>>> rbd-mirror might do an intra-cluster job. >>>> >>>> Are you able to judge how much work would need to be done, in order to >>>> create a one-shot, intra-cluster version of rbd-mirror? Might it even be >>>> something that could be a simple enhancement? >>> >>> >>> You might be interested in the deep-copy feature that will be included >>> in the Mimic release. By running "rbd deep-copy <src-image> >>> <dst-image>", it will fully copy the image, including snapshots and >>> parentage, to a new image. There is also work-in-progress for online >>> image migration [1] that will allow you to keep using the image while >>> it's being migrated to a new destination image. Both of these are >>> probably more suited to your needs than the heavy-weight RBD mirroring >>> process -- especially if you are only interested in the first step >>> since RBD mirroring now directly utilizes the deep-copy feature for >>> the initial image sync. >> >> >> ... also forgot to mention "rbd export --export-format 2" / "rbd >> import --export-format 2" that will also deeply export/import all >> snapshots associated with an image and that feature is available in >> the Luminous release. >> >>>> Thank you for any information and / or opinion you care to share! >>>> >>>> With regards, >>>> Jens >>>> >>> >>> [1] https://github.com/ceph/ceph/pull/15831 >>> >>> -- >>> Jason >> >> >> >> >> -- >> Jason >> _______________________________________________ >> ceph-users mailing list >> ceph-users@lists.ceph.com >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > > -- > Eugen Block voice : +49-40-559 51 75 > NDE Netzdesign und -entwicklung AG fax : +49-40-559 51 77 > Postfach 61 03 15 > D-22423 Hamburg e-mail : ebl...@nde.ag > > Vorsitzende des Aufsichtsrates: Angelika Mozdzen > Sitz und Registergericht: Hamburg, HRB 90934 > Vorstand: Jens-U. Mozdzen > USt-IdNr. DE 814 013 983 > -- Jason _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
