Dear Michael, I was also wondering whether deleting the broken pool could clean up everything. The difficulty is, that while migrating a pool to new devices is easy via a crush rule change, migrating data between pools is not so easy. In particular, if you can't afford downtime. In case you can afford some downtime, it might be possible to migrate fast by creating a new pool and use the pool copy command to migrate the data (rados cppool ...). Its important that the FS is shutdown (no MDS active) during this copy process. After copy, one could either rename the pools to have the copy match the fs data pool name, or change the data pool at the top level directory. You might need to set some pool meta data by hand, notably, the fs tag. Having said that, I have no idea how a ceph fs reacts if presented with a replacement data pool. Although I don't believe that meta data contains the pool IDs, I cannot exclude that complication. The copy pool variant should be tested with an isolated FS first. The other option is what you describe, create a new data pool, make the fs root placed on this pool and copy every file onto itself. This should also do the trick. However, with this method you will not be able to get rid of the broken pool. After the copy, you could, however, reduce the number of PGs to below the unhealthy one and the broken PG(s) might get deleted cleanly. Then you still have a surplus pool, but at least all PGs are clean. I hope one of these will work. Please post your experience here. Best regards, ================= Frank Schilder AIT Risø Campus Bygning 109, rum S14 ________________________________________ From: Michael Thomas <wart@xxxxxxxxxxx> Sent: 22 November 2020 18:29:16 To: Frank Schilder; ceph-users@xxxxxxx Subject: Re: Re: multiple OSD crash, unfound objects On 10/23/20 3:07 AM, Frank Schilder wrote: > Hi Michael. > >> I still don't see any traffic to the pool, though I'm also unsure how much traffic is to be expected. > > Probably not much. If ceph df shows that the pool contains some objects, I guess that's sorted. > > That osdmaptool crashes indicates that your cluster runs with corrupted internal data. I tested your crush map and you should get complete PGs for the fs data pool. That you don't and that osdmaptool crashes points at a corruption of internal data. I'm afraid this is the point where you need support from ceph developers and should file a tracker report (https://tracker.ceph.com/projects/ceph/issues). A short description of the origin of the situation with the osdmaptool output and a reference to this thread linked in should be sufficient. Please post a link to the ticket here. https://tracker.ceph.com/issues/48059 > In parallel, you should probably open a new thread focussed on the osd map corruption. Maybe there are low-level commands to repair it. Will do. > You should wait with trying to clean up the unfound objects until this is resolved. Not sure about adding further storage either. To me, this sounds quite serious. Another approach that I'm considering is to create a new pool using the same set of OSDs, adding it to the set of cephfs data pools, and migrating the data from the "broken" pool to the new pool. I have some additional unused storage that I could add to this new pool, if I can figure out the right crush rules to make sure they don't get used for the "broken" pool too. --Mike _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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