On 09/06/2026 14:10, Andrej Filipcic via ceph-users wrote:

Hi,

I have a problem with large amounts of dark data/orphans on cephfs data pool. Data is stored mostly on a 8+3 EC pool (cephfs_data_echdd).

There is ~5.6PiB stored on /ceph, shown by ceph.dir.rbytes with 132M files and 139M rentries. The pool shows 7PiB stored and 9.7PiB used consistent with 8+3 EC. The layout for most files: ceph.dir.layout="stripe_unit=16777216 stripe_count=1 object_size=16777216 pool=cephfs_data_echdd"

But there is 1.4PiB discrepancy between the pool and the filesystem which I cannot explain and I suspect there are a lot of orphan objects there. I have run mds scrub on / and ~mdsdir as well. There is some mds damage on some old small files (~400 files), which I do not think it's relevant here.

Hello, We had a similar issue last year with a group of users that created and removed files at a very high rate. Have you read https://docs.clyso.com/docs/kb/cephfs/#cephfs-pool-data-usage-growth-without... ? We increased the purge rate parameters (very) aggressively to get back to a comfortable situation (i.e. not a pool w/ near full warnings). Loïc. -- | Loīc Tortay <tortay@cc.in2p3.fr> - IN2P3 Computing Centre |