[ceph-users] rbd mirror journal data

Jason Dillaman jdillama at redhat.com
Tue Nov 6 05:25:44 PST 2018


On Tue, Nov 6, 2018 at 1:12 AM Wei Jin <wjin.cn at gmail.com> wrote:
>
> Thanks.
> I found that both minimum and active set are very large in my cluster, is it expected?
> By the way, I do snapshot for each image half an hour,and keep snapshots for two days.
>
> Journal status:
>
> minimum_set: 671839
> active_set: 1197917
> registered clients:
>         [id=, commit_position=[positions=[[object_number=4791670, tag_tid=3, entry_tid=4146742458], [object_number=4791669, tag_tid=3, entry_tid=4146742457], [object_number=4791668, tag_tid=3, entry_tid=4146742456], [object_number=4791671, tag_tid=3, entry_tid=4146742455]]], state=connected]
>         [id=89024ad3-57a7-42cc-99d4-67f33b093704, commit_position=[positions=[[object_number=2687357, tag_tid=3, entry_tid=1188516421], [object_number=2687356, tag_tid=3, entry_tid=1188516420], [object_number=2687359, tag_tid=3, entry_tid=1188516419], [object_number=2687358, tag_tid=3, entry_tid=1188516418]]], state=connected]
>

Are you attempting to run "rbd-mirror" daemon on a remote cluster? It
just appears like either the daemon is not running or that it's so far
behind that it's just not able to keep up with the IO workload of the
image. You can run "rbd journal disconnect --image <image-id>
--client-id=89024ad3-57a7-42cc-99d4-67f33b093704" to force-disconnect
the remote client and start the journal trimming process.

> > On Nov 6, 2018, at 3:39 AM, Jason Dillaman <jdillama at redhat.com> wrote:
> >
> > On Sun, Nov 4, 2018 at 11:59 PM Wei Jin <wjin.cn at gmail.com> wrote:
> >>
> >> Hi, Jason,
> >>
> >> I have a question about rbd mirroring. When enable mirroring, we observed that there are a lot of objects prefix with journal_data, thus it consumes a lot of disk space.
> >>
> >> When will these journal objects be deleted? And are there any parameters to accelerate it?
> >> Thanks.
> >>
> >
> > Journal data objects should be automatically deleted when the journal
> > is trimmed beyond the position of the object. If you run "rbd journal
> > status --image <image-name>", you should be able to see the minimum
> > in-use set and the current active set for new journal entries:
> >
> > $ rbd --cluster cluster1 journal status --image image1
> > minimum_set: 7
> > active_set: 8
> > registered clients:
> > [id=, commit_position=[positions=[[object_number=33, tag_tid=2,
> > entry_tid=49153], [object_number=32, tag_tid=2, entry_tid=49152],
> > [object_number=35, tag_tid=2, entry_tid=49151], [object_number=34,
> > tag_tid=2, entry_tid=49150]]], state=connected]
> > [id=81672c30-d735-46d4-a30a-53c221954d0e,
> > commit_position=[positions=[[object_number=30, tag_tid=2,
> > entry_tid=48034], [object_number=29, tag_tid=2, entry_tid=48033],
> > [object_number=28, tag_tid=2, entry_tid=48032], [object_number=31,
> > tag_tid=2, entry_tid=48031]]], state=connected]
> >
> > $ rados --cluster cluster1 --pool rbd ls | grep journal_data | sort
> > journal_data.1.1029b4577f90.28
> > journal_data.1.1029b4577f90.29
> > journal_data.1.1029b4577f90.30
> > journal_data.1.1029b4577f90.31
> > journal_data.1.1029b4577f90.32
> > journal_data.1.1029b4577f90.33
> > journal_data.1.1029b4577f90.34
> > journal_data.1.1029b4577f90.35
> > <......>
> >
> > $ rbd --cluster cluster1 journal status --image image1
> > minimum_set: 8
> > active_set: 8
> > registered clients:
> > [id=, commit_position=[positions=[[object_number=33, tag_tid=2,
> > entry_tid=49153], [object_number=32, tag_tid=2, entry_tid=49152],
> > [object_number=35, tag_tid=2, entry_tid=49151], [object_number=34,
> > tag_tid=2, entry_tid=49150]]], state=connected]
> > [id=81672c30-d735-46d4-a30a-53c221954d0e,
> > commit_position=[positions=[[object_number=33, tag_tid=2,
> > entry_tid=49153], [object_number=32, tag_tid=2, entry_tid=49152],
> > [object_number=35, tag_tid=2, entry_tid=49151], [object_number=34,
> > tag_tid=2, entry_tid=49150]]], state=connected]
> >
> > $ rados --cluster cluster1 --pool rbd ls | grep journal_data | sort
> > journal_data.1.1029b4577f90.32
> > journal_data.1.1029b4577f90.33
> > journal_data.1.1029b4577f90.34
> > journal_data.1.1029b4577f90.35
> >
> > --
> > Jason
>


-- 
Jason


More information about the ceph-users mailing list