[LU-5895] lfs: data version changed during migration

• Type: Bug
• Resolution: Unresolved
• Priority: Major
• Affects Version/s: Lustre 2.7.0
• Labels: patch
• Environment: head of tree + LU-4840
• Severity: 3
• Assignee: Ben Evans (Inactive)
• Reporter: Frank Zago (Inactive)

Description

Archiving, releasing then migrating leads to a "data version changed during migration":

# cd /mnt/lustre
# cp /usr/bin/zip .
# lfs getstripe zip
zip
lmm_stripe_count:   1
lmm_stripe_size:    1048576
lmm_pattern:        1
lmm_layout_gen:     0
lmm_stripe_offset:  1
	obdidx		 objid		 objid		 group
	     1	             2	          0x2	             0
# lfs hsm_archive zip
# lfs hsm_release zip
# lfs hsm_state zip
zip: (0x0000000d) released exists archived, archive_id:1
# lfs getstripe zip
zip
lmm_stripe_count:   1
lmm_stripe_size:    1048576
lmm_pattern:        80000001
lmm_layout_gen:     1
lmm_stripe_offset:  0
# lfs migrate -o 0 zip
/root/lustre-cleanup/lustre/utils/lfs: zip: data version changed during migration
error: migrate: migrate stripe file 'zip' failed

I think the file is restored first, then migrated, but its data version is not updated. Which lead to the following questions:

• is it correct to force a restore of an archived file when asking for a migrate operation?
• couldn't the file be restored directly to the proper OST/stripe size, ...?
• although an error is reported, the file is present and complete, so the operation actually completed properly. What if that was another kind of error? Would we get a data corruption?

Issue Links

• is related to: LU-5896 lfs: can't release a migrated file