ram3, SZ:00065472 F:0 S:1 DN:3 [ 6742.346070] md: rdev superblock: [ 6742.346073] md: SB: (V:1.0.0) ID:<369aad81.00000000.00000000.00000000> CT:9a322a9c [ 6742.346077] md: L-1507699579 S976570180 ND:48 RD:0 md0 LO:65536 CS:196610 [ 6742.346081] md: UT:00000018 ST:0 AD:131048 WD:0 FD:8 SD:0 CSUM:00000000 E:00000000 [ 6742.346084] D 0: DISK [ 6742.346089] D 1: DISK [ 6742.346092] D 2: DISK [ 6742.346096] D 3: DISK [ 6742.346102] md: THIS: DISK ... [ 6742.346219] md: ********************************** [ 6742.346221] Here md1 is metadata 0.90.0, and md0 is metadata 1.2 After some more code to distinguish these two types of superblock, in this patch, it will generate dump information like: [ 7906.755790] [ 7906.755799] md: ********************************** [ 7906.755802] md: * * [ 7906.755804] md: ********************************** [ 7906.755808] md1: [ 7906.755819] md: rdev ram7, SZ:00065472 F:0 S:1 DN:3 [ 7906.755821] md: rdev superblock (MJ:0): [ 7906.755826] md: SB: (V:0.90.0) ID:<3fca7a0d.a612bfed.5f9f1645.801e9ee6> CT:491989f3 [ 7906.755830] md: L5 S00065472 ND:4 RD:4 md1 LO:2 CS:65536 [ 7906.755834] md: UT:491989f3 ST:1 AD:4 WD:4 FD:0 SD:0 CSUM:00fb52ad E:00000001 [ 7906.755836] D 0: DISK [ 7906.755842] D 1: DISK [ 7906.755845] D 2: DISK [ 7906.755849] D 3: DISK [ 7906.755855] md: THIS: DISK ... [ 7906.755972] md0: [ 7906.755981] md: rdev ram3, SZ:00065472 F:0 S:1 DN:3 [ 7906.755984] md: rdev superblock (MJ:1): [ 7906.755989] md: SB: (V:1) (F:0) Array-ID:<5fbcf158:55aa:5fbe:9a79:1e939880dcbd> [ 7906.755990] md: Name: "DG5:0" CT:1226410480 [ 7906.755998] md: L5 SZ130944 RD:4 LO:2 CS:128 DO:24 DS:131048 SO:8 RO:0 [ 7906.755999] md: Dev:00000003 UUID: 9194d744:87f7:a448:85f2:7497b84ce30a [ 7906.756001] md: (F:0) UT:1226410480 Events:0 ResyncOffset:-1 CSUM:0dbcd829 [ 7906.756003] md: (MaxDev:384) ... [ 7906.756113] md: ********************************** [ 7906.756116] this md0 (metadata 1.2) information dumping is exactly according to struct mdp_superblock_1. Signed-off-by: Cheng Renquan Cc: Neil Brown Cc: Dan Williams Signed-off-by: Andrew Morton Signed-off-by: NeilBrown