[LU-4295] removing files on deactivated OST doesn't free up space

• Status: Resolved
• Project: Lustre
• Affects Version/s: Lustre 2.4.1
• Type: Bug
• Priority: Major
• Reporter: Wolfgang Baudler
• Assignee: WC Triage
• Resolution: Not a Bug
• Labels: server

Environment

Lustre 2.4.1 RHEL6 2.6.32-358.18.1.el6_lustre.x86_64

• Severity: 3
• Epic: metadata, server

Description

One OST is deactivated on the MDS via "lctl --device 56 deactivate".

Now when I try to drain the OST, I can remove (rm) files without an error message, but no space gets freed up on that OST as shown in "lfs df" output.

I assume it only removed the inode/object on the MDS, but doesn't touch the deactivated OST, leaving all the migrated files behind as orphaned objects on the OST, which is pretty bad.

If I do the same migration with the OST active, space as shown in "lfs df" does get freed up correctly.

Issue Links

• duplicates: LU-7012 files not being deleted from OST afte...
• is related to: LU-4825 lfs migrate not freeing space on OST
• is related to: LU-7668 permanently remove deactivated OSTs f...

Comments

[Andreas Dilger]

The MDS keeps a log of the objects deleted on the deactivated OST (this can happen if the OST is offline for any reason), and they should be deleted if the OST is activated again.

[Wolfgang Baudler]

Well, in practice this did not work. I have reactivated the OST and then drained it with a script using

lfs getstripe -v -r --obd $OST_PARAM $DIR

to find all the files on the OST

(since lfs_migrate is currently broken for 2.4.1)

Now, after this draining is done lfs gestripe doesn't list any files any more on this OST, but lfs df still shows over 200GB of used disk space. So there must be some orphaned objects on there, presumably left over when I tried to drain the OST in a deactivated state as initially described.