[ceph-users] Re: Preferred order of operations when changing crush map and pool rules

On 3/30/21 3:00 PM, Thomas Hukkelberg wrote:

Any thoughts or insight on how to achieve this with minimal data movement and risk of cluster downtime would be welcome!

I would do so with Dan's "upmap-remap" script [1]. See [2] for his presentation. We have used that quite a few times now (also to do cluster expansions) and it works great. Especially that you can "pause" any movement and obtain "HEALTH_OK" are really nice benefits. Gr. Stefan [1]: https://github.com/HeinleinSupport/cern-ceph-scripts/blob/master/tools/upmap... [2]: https://www.slideshare.net/Inktank_Ceph/ceph-day-berlin-mastering-ceph-opera...