On Friday, July 5, 2019 11:28:32 AM CDT Caspar Smit wrote: > Kyle, > > Was the cluster still backfilling when you removed osd 6 or did you only > check its utilization? Yes, still backfilling. > > Running an EC pool with m=1 is a bad idea. EC pool min_size = k+1 so losing > a single OSD results in inaccessible data. > Your incomplete PG's are probably all EC pool pgs, please verify. Yes, also correct. > > If the above statement is true, you could *temporarily* set min_size to 2 > (on your EC pools) to get back access to your data again but this is a very > dangerous action. Losing another OSD during this period results in actual > data loss. This resolved the issue. I had seen reducing min_size mentioned elsewhere, but for some reason I thought that applied only to replicated pools. Thank you! > > Kind regards, > Caspar Smit > > Op vr 5 jul. 2019 om 01:17 schreef Kyle <aradian@xxxxxxxxx>: > > Hello, > > > > I'm working with a small ceph cluster (about 10TB, 7-9 OSDs, all Bluestore > > on > > lvm) and recently ran into a problem with 17 pgs marked as incomplete > > after > > adding/removing OSDs. > > > > Here's the sequence of events: > > 1. 7 osds in the cluster, health is OK, all pgs are active+clean > > 2. 3 new osds on a new host are added, lots of backfilling in progress > > 3. osd 6 needs to be removed, so we do "ceph osd crush reweight osd.6 0" > > 4. after a few hours we see "min osd.6 with 0 pgs" from "ceph osd > > utilization" > > 5. ceph osd out 6 > > 6. systemctl stop ceph-osd@6 > > 7. the drive backing osd 6 is pulled and wiped > > 8. backfilling has now finished all pgs are active+clean except for 17 > > incomplete pgs > > > > From reading the docs, it sounds like there has been unrecoverable data > > loss > > in those 17 pgs. That raises some questions for me: > > > > Was "ceph osd utilization" only showing a goal of 0 pgs allocated instead > > of > > the current actual allocation? > > > > Why is there data loss from a single osd being removed? Shouldn't that be > > recoverable? > > All pools in the cluster are either replicated 3 or erasure-coded k=2,m=1 > > with > > default "host" failure domain. They shouldn't suffer data loss with a > > single > > osd being removed even if there were no reweighting beforehand. Does the > > backfilling temporarily reduce data durability in some way? > > > > Is there a way to see which pgs actually have data on a given osd? > > > > I attached an example of one of the incomplete pgs. > > > > Thanks for any help, > > > > Kyle_______________________________________________ > > ceph-users mailing list > > ceph-users@xxxxxxxxxxxxxx > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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