osd df is misleading when using external DB devices, they are always counted as 100% full there Paul -- Paul Emmerich Looking for help with your Ceph cluster? Contact us at https://croit.io croit GmbH Freseniusstr. 31h 81247 München www.croit.io Tel: +49 89 1896585 90 On Wed, May 13, 2020 at 11:40 AM Denis Krienbühl <denis@href.ch> wrote:
Hi
On one of our Ceph clusters, some OSDs have been marked as full. Since this is a staging cluster that does not have much data on it, this is strange.
Looking at the full OSDs through “ceph osd df” I figured out that the space is mostly used by metadata:
SIZE: 122 GiB USE: 118 GiB DATA: 2.4 GiB META: 116 GiB
We run mimic, and for the affected OSDs we use a db device (nvme) in addition to the primary device (hdd).
In the logs we see the following errors:
2020-05-12 17:10:26.089 7f183f604700 1 bluefs _allocate failed to allocate 0x400000 on bdev 1, free 0x0; fallback to bdev 2 2020-05-12 17:10:27.113 7f183f604700 1 bluestore(/var/lib/ceph/osd/ceph-8) _balance_bluefs_freespace gifting 0x180a000000~400000 to bluefs 2020-05-12 17:10:27.153 7f183f604700 1 bluefs add_block_extent bdev 2 0x180a000000~400000
We assume it is an issue with Rocksdb, as the following call will quickly fix the problem:
ceph daemon osd.8 compact
The question is, why is this happening? I would think that “compact" is something that runs automatically from time to time, but I’m not sure.
Is it on us to run this regularly?
Any pointers are welcome. I’m quite new to Ceph :)
Cheers,
Denis _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io