[LU-18468] Md5 chksum fails on the mirror file created by dd with bs=4k after doing mirror resync and delete

• Type: Bug
• Resolution: Unresolved
• Priority: Blocker
• Severity: 3
• Assignee: Alex Zhuravlev
• Reporter: Emoly Liu

Description

I hit this issue when I am working on the patch of LU-13720, in sanity.sh test_211. 
If bs=4k (probably multiple of 4K), md5 chksum always fails on the mirror file created by dd after doing mirror resync and delete.

It can be easily reproduced by the following scripts:

# dd if=/dev/zero of=/mnt/lustre/abc bs=4k count=10 oflag=direct
# lfs mirror extend -N /mnt/lustre/abc
# dd if=/dev/zero of=/mnt/lustre/abc bs=4k count=1 oflag=direct
# md5sum /mnt/lustre/abc
620f0b67a91f7f74151bc5be745b7110  /mnt/lustre/abc

# lfs mirror resync /mnt/lustre/abc
# lfs mirror delete --mirror-id=1 /mnt/lustre/abc
# md5sum /mnt/lustre/abc
ab893875d697a3145af5eed5309bee26  /mnt/lustre/abc

Md5 check can pass if bs is set to other than multiple of 4k, e.g. 1k.

Issue Links

• is related to: LU-13720 "lfs mirror delete" should resync file if needed
• is related to: LU-9771 FLR1: Landing tickets for File Level Redundancy Phase 1