[LU-16423] 'lfs migrate' is creating multiple sets of objects

• Status: Resolved
• Project: Lustre
• Type: Bug
• Priority: Minor
• Reporter: Andreas Dilger
• Assignee: WC Triage
• Resolution: Not a Bug
• Severity: 3

Description

When running "lfs migrate" on a PFL file, it appears that the client/MDS are needlessly creating multiple sets of OST objects:

# lfs setstripe -E 1M -c 1 -E 16M -c 4 -E eof -c -1 /mnt/testfs/pfl
# fallocate -L 4M /mnt/testfs/pfl
# lfs getstripe /mnt/testfs/pfl | grep l_ost_idx
      - 0: { l_ost_idx: 0, l_fid: [0x100000000:0xed5:0x0] }
      - 0: { l_ost_idx: 3, l_fid: [0x100030000:0x653:0x0] }
      - 1: { l_ost_idx: 1, l_fid: [0x100010000:0xb93:0x0] }
      - 2: { l_ost_idx: 2, l_fid: [0x100020000:0x62c:0x0] }
      - 3: { l_ost_idx: 0, l_fid: [0x100000000:0xed7:0x0] }
# lfs migrate /mnt/testfs/pfl
# lfs getstripe /mnt/testfs/pfl | grep l_ost_idx
      - 0: { l_ost_idx: 0, l_fid: [0x100000000:0xed8:0x0] }
      - 0: { l_ost_idx: 3, l_fid: [0x100030000:0x655:0x0] }
      - 1: { l_ost_idx: 1, l_fid: [0x100010000:0xb95:0x0] }
      - 2: { l_ost_idx: 2, l_fid: [0x100020000:0x62e:0x0] }
      - 3: { l_ost_idx: 0, l_fid: [0x100000000:0xeda:0x0] }
# lfs migrate /mnt/testfs/pfl
# lfs getstripe /mnt/testfs/pfl | grep l_ost_idx
      - 0: { l_ost_idx: 0, l_fid: [0x100000000:0xedb:0x0] }
      - 0: { l_ost_idx: 3, l_fid: [0x100030000:0x657:0x0] }
      - 1: { l_ost_idx: 1, l_fid: [0x100010000:0xb97:0x0] }
      - 2: { l_ost_idx: 2, l_fid: [0x100020000:0x630:0x0] }
      - 3: { l_ost_idx: 0, l_fid: [0x100000000:0xedd:0x0] }
# lfs migrate /mnt/testfs/pfl
# lfs getstripe /mnt/testfs/pfl | grep l_ost_idx
      - 0: { l_ost_idx: 0, l_fid: [0x100000000:0xede:0x0] }
      - 0: { l_ost_idx: 3, l_fid: [0x100030000:0x659:0x0] }
      - 1: { l_ost_idx: 1, l_fid: [0x100010000:0xb99:0x0] }
      - 2: { l_ost_idx: 2, l_fid: [0x100020000:0x632:0x0] }
      - 3: { l_ost_idx: 0, l_fid: [0x100000000:0xee0:0x0] }

As can be seen from the above, each "lfs migrate" command increments most OST FIDs by two, and OST0000 by three (because it has two separate objects for this file). The filesystem has 4 OSTs.

Comments

[Andreas Dilger]

I tested this again on master with both "lfs migrate" and "lfs_migrate" and wasn't able to reproduce it.