>On Tue, Apr 9, 2019 at 10:40 AM Magnus Grönlund <magnus@xxxxxxxxxxx> wrote:
>>
>> Hi,
>> We have configured one-way replication of pools between a production cluster and a backup cluster. But unfortunately the rbd-mirror or the backup cluster is unable to keep up with the production cluster so the replication fails to reach replaying state.
>
>Hmm, it's odd that they don't at least reach the replaying state. Are
>they still performing the initial sync?
There are three pools we try to mirror, (glance, cinder, and nova, no points for guessing what the cluster is used for :) ),
the glance and cinder pools are smaller and sees limited write activity, and the mirroring works, the nova pool which is the largest and has 90% of the write activity never leaves the "unknown" state.
# rbd mirror pool status cinder
health: OK
images: 892 total
890 replaying
2 stopped
#
# rbd mirror pool status nova
health: WARNING
images: 2479 total
2479 unknown
#
The production clsuter has 5k writes/s on average and the backup cluster has 1-2k writes/s on average. The production cluster is bigger and has better specs. I thought that the backup cluster would be able to keep up but it looks like I was wrong.
>> And the journals on the rbd volumes keep growing...
>>
>> Is it enough to simply disable the mirroring of the pool (rbd mirror pool disable <pool>) and that will remove the lagging reader from the journals and shrink them, or is there anything else that has to be done?
>
>You can either disable the journaling feature on the image(s) since
>there is no point to leave it on if you aren't using mirroring, or run
>"rbd mirror pool disable <pool>" to purge the journals.
Thanks for the confirmation.
I will stop the mirror of the nova pool and try to figure out if there is anything we can do to get the backup cluster to keep up.
>> Best regards
>> /Magnus
>> _______________________________________________
>> ceph-users mailing list
>
>--
>Jason
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