[LU-4569] Posix copytool import a file using only its FID

• Status: Resolved
• Project: Lustre
• Fix Version/s: Lustre 2.6.0, Lustre 2.5.2
• Type: Improvement
• Priority: Minor
• Reporter: Henri Doreau (Inactive)
• Assignee: Bruno Faccini (Inactive)
• Resolution: Fixed
• Labels: HSM, patch

Description

The posix copytool imports files that are designated by their path in the backend, despite being itself the only one to know this path.

We propose a slight improvement to make the posix CT also accept a FID as import source parameter (from which the path can be rebuilt). This would allow easy "undeletion" of archived files:

lhsmtool_posix --import <fid> /mnt/lustre/undelete ...

Comments

[Henri Doreau (Inactive)]

Patch at http://review.whamcloud.com/9075

[Peter Jones]

Bruno

Could you please take care of this patch?

Thanks

Peter

[Bruno Faccini (Inactive)]

The only few auto-tests errors are unrelated to this patch. Looks good to me.

[Henri Doreau (Inactive)]

Any update on this?

[Bruno Faccini (Inactive)]

Hello Henry, reviews are in progress so I think your patch should land soon now!

[Peter Jones]

Landed for 2.6

[James Nunez (Inactive)]

Patch for b2_5 at http://review.whamcloud.com/#/c/10132/

[jacques-charles lafoucriere]

This patch missed the following use case:
1) create/archive a file1 with FID1
2) import a new file2 from FID1
3) restore file2
4) file1 and file2 share the same archive in backend so it will be corrupted after next archive of file1 or file2

solution:
(2) must be forbidden if FID1 exists in Lustre

[Henri Doreau (Inactive)]

Thanks JC. I will submit a fix for master and an updated patch for 2.5.

[Henri Doreau (Inactive)]

Patch for master: http://review.whamcloud.com/10185
The problem was already present when importing by path, the patch aims at fixing both cases.

[Henri Doreau (Inactive)]

The check on import by path breaks sanity-hsm. Patchset #2 only performs the existence check when importing FIDs (more error-prone maybe?). Also, the extra access() call has a non-negligible impact, that might be undesirable when importing large directory tree which is typically what import-by-path would be useful for.

The problem is that sanity-hsm directly copies files to the archive without following the naming scheme used by the posix copytool. An option would be to copy those files into lustre, archiving them and removing them from lustre, but this is not totally equivalent (it involves many more components). Let me know if some solution is preferred.

[Peter Jones]

Both patches landed to 2.6; will be landed to b2_5 separately