On 10/6/2020 4:43 PM, Stefan Kooman wrote:
On 2020-10-06 15:27, Igor Fedotov wrote:
I'm working on improving PG removal in
master, see:
https://github.com/ceph/ceph/pull/37496
Hopefully this will help in case of "cleanup after rebalancing" issue
which you presumably had.
That would be great. Does the offline compaction with
the
ceph-kvstore-tool follows a completely different removal procedure and
is that why it's that much faster?
First of all - compaction is primarily about rearranging DB data in an
optimal way not removing it. Compaction after massive removals just
optimizes DB data layout and eliminates all the leftovers from the
previous rewrites/removals that negatively impact DB performance.
Offline compaction work in an exclusive access mode and doesn't care
about parallel DB operations. Hence it's presumably much more effective
comparing to the online one. Not to mention that the latter is rather
partial...
>
> @Kristof:
>
https://github.com/ceph/ceph/commit/93e4c56ecc13560e0dad69aaa67afc3ca053fb4c
> is a commit by Wido that would help to enable compaction at OSD (re)start.
>
> Gr. Stefan