[LU-15557] creating/breaking mirror should not change file timestamps

• Type: Improvement
• Resolution: Not a Bug
• Priority: Minor
• Affects Version/s: Lustre 2.12.6
• Severity: 3
• Assignee: Colin Faber
• Reporter: Mahmoud Hanafi

Description

When a file is mirrored and the mirrored is broken file time stamps should be preserved. Here we see that ctime and mtime change to the mirror creation time.

Initial File:

 # stat testfile
  File: 'testfile'
  Size: 59535     	Blocks: 120        IO Block: 4194304 regular file
Device: 521e79ech/1377729004d	Inode: 342273918398214817  Links: 1
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2022-02-14 15:48:45.000000000 -0800
Modify: 2022-02-14 15:48:45.000000000 -0800
Change: 2022-02-14 15:48:45.000000000 -0800

 
Now we mirror

 # date; lfs mirror extend -N S 1M -c 1 -p hdd-pool testfile
Mon Feb 14 15:50:27 PST 2022

State the File and layout

# stat testfile
  File: 'testfile'
  Size: 59535     	Blocks: 120        IO Block: 4194304 regular file
Device: 521e79ech/1377729004d	Inode: 342273918398214817  Links: 1
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2022-02-14 15:48:45.000000000 -0800
Modify: 2022-02-14 15:48:45.000000000 -0800
Change: 2022-02-14 15:48:45.000000000 -0800
 Birth: -
pfe25 /nobackupp18/mhanafi # lfs getstripe testfile
testfile
  lcm_layout_gen:    1
  lcm_mirror_count:  2
  lcm_entry_count:   4
    lcme_id:             65537
    lcme_mirror_id:      1
    lcme_flags:          init,prefer
    lcme_extent.e_start: 0
    lcme_extent.e_end:   268435456
      lmm_stripe_count:  1
      lmm_stripe_size:   16777216
      lmm_pattern:       raid0
      lmm_layout_gen:    0
      lmm_stripe_offset: 109
      lmm_pool:          ssd-pool
      lmm_objects:
      - 0: { l_ost_idx: 109, l_fid: [0x90000040a:0x53990:0x0] }

    lcme_id:             65538
    lcme_mirror_id:      1
    lcme_flags:          prefer
    lcme_extent.e_start: 268435456
    lcme_extent.e_end:   5368709120
      lmm_stripe_count:  -1
      lmm_stripe_size:   16777216
      lmm_pattern:       raid0
      lmm_layout_gen:    0
      lmm_stripe_offset: -1
      lmm_pool:          ssd-pool

    lcme_id:             65539
    lcme_mirror_id:      1
    lcme_flags:          0
    lcme_extent.e_start: 5368709120
    lcme_extent.e_end:   EOF
      lmm_stripe_count:  16
      lmm_stripe_size:   16777216
      lmm_pattern:       raid0
      lmm_layout_gen:    0
      lmm_stripe_offset: -1
      lmm_pool:          hdd-pool

    lcme_id:             131073
    lcme_mirror_id:      2
    lcme_flags:          init
    lcme_extent.e_start: 0
    lcme_extent.e_end:   EOF
      lmm_stripe_count:  1
      lmm_stripe_size:   1048576
      lmm_pattern:       raid0
      lmm_layout_gen:    0
      lmm_stripe_offset: 0
      lmm_pool:          hdd-pool
      lmm_objects:
      - 0: { l_ost_idx: 0, l_fid: [0x2c0000409:0x30c3e:0x0] }

Break the mirror and stat the file. File ctime and atime has changed.

date; lfs mirror split -d --mirror-id 1 testfile
Mon Feb 14 15:51:31 PST 2022

 # stat testfile
  File: 'testfile'
  Size: 59535     	Blocks: 120        IO Block: 4194304 regular file
Device: 521e79ech/1377729004d	Inode: 342273918398214817  Links: 1
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2022-02-14 15:50:27.000000000 -0800
Modify: 2022-02-14 15:48:45.000000000 -0800
Change: 2022-02-14 15:50:27.000000000 -0800
 Birth: -

Issue Links

• is duplicated by: LU-14508 lfs mirror operations do not preserve timestamps