[LU-4140] Volatile files have CREATE changelog record but nothing to tell it is removed.

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.6.0, Lustre 2.5.4
• Affects Version/s: Lustre 2.4.2, Lustre 2.5.1
• Labels: HSM
• Severity: 3
• Assignee: Bruno Faccini (Inactive)
• Reporter: Aurelien Degremont (Inactive)

Description

When volatile files are created, a CREATE changelog record is emitted. But no record says that file was also immediately unlinked.

Either we need a UNLINK record for that FID, or a special flag in CLOSE record.

By the way, I do not think lustre_rsync is handling volatile files, but more especially it should handled LAYOUT records rather than volatile files.

Issue Links

• is related to: LU-3696 sanity test_17m, test_17n: e2fsck unattached inodes failure

Comments

[Jodi Levi (Inactive)]

Patch landed to Master.

[Bruno Faccini (Inactive)]

I did some extended testing and it appears that with this patch there is no longer a "i_am_nobody" orphan inode left for each hsm_release operation nor a ".^L^S^T^R:VOLATILE:: ..." one for each hsm_restore operation, this is for LU-3696..
And I also checked it also fixes/avoids the unecessary reporting of ChangeLog events for these volatile files, this is for LU-4140.

[Andreas Dilger]

I pushed http://review.whamcloud.com/10179 to try and fix the volatile file problem, and also avoid creating ChangeLog entries for volatile files.

[Andreas Dilger]

I've reopened LU-3696 to track the fix for MDT object leak for volatile files separately. That problem is critical since it is leaking space in the filesystem (both on the MDT and OST) for every volatile file used and needs to be back-ported to 2.4.x and 2.5.x. The presence/absence of a changelog record for volatile files is a much more complex issue and I think it can be fixed and landed separately.

[Bruno Faccini (Inactive)]

I have been able to confirm that this issue is linked to the fact that volatile file usage is causing MDT objects orphans/leak. I will (finaly/hopefully?) have time now to push a patch to fix ...

[Bruno Faccini (Inactive)]

Hello Aurelien, I am back on this now, and I will check the issue you raised about "no CL events for open-unlink files, even it they are not volatile ones", and let you know soon.