Hi Eric,
It's not an in-kernel driver, I need to rebuild it each time the kernel is
updated.
The output of the dd command follows:
$ sudo dd if=/dev/sdc bs=512 count=128 iflag=direct | hexdump -C | grep XFSB
128+0 records in
128+0 records out
65536 bytes (66 kB) copied, 0.0241381 s, 2.7 MB/s
I thought the XFSB marked the start of the superblock... and it not being there
would be a Bad Thing??
without the "| grep XFSB" the output looks like:
$ sudo dd if=/dev/sdc bs=512 count=128 iflag=direct | hexdump -C
00000000 33 c0 8e d0 bc 00 7c fb 50 07 50 1f fc be 1b 7c |3.....|.P.P....||
00000010 bf 1b 06 50 57 b9 e5 01 f3 a4 cb bd be 07 b1 04 |...PW...........|
00000020 38 6e 00 7c 09 75 13 83 c5 10 e2 f4 cd 18 8b f5 |8n.|.u..........|
00000030 83 c6 10 49 74 19 38 2c 74 f6 a0 b5 07 b4 07 8b |...It.8,t.......|
00000040 f0 ac 3c 00 74 fc bb 07 00 b4 0e cd 10 eb f2 88 |..<.t...........|
00000050 4e 10 e8 46 00 73 2a fe 46 10 80 7e 04 0b 74 0b |N..F.s*.F..~..t.|
00000060 80 7e 04 0c 74 05 a0 b6 07 75 d2 80 46 02 06 83 |.~..t....u..F...|
00000070 46 08 06 83 56 0a 00 e8 21 00 73 05 a0 b6 07 eb |F...V...!.s.....|
00000080 bc 81 3e fe 7d 55 aa 74 0b 80 7e 10 00 74 c8 a0 |..>.}U.t..~..t..|
00000090 b7 07 eb a9 8b fc 1e 57 8b f5 cb bf 05 00 8a 56 |.......W.......V|
000000a0 00 b4 08 cd 13 72 23 8a c1 24 3f 98 8a de 8a fc |.....r#..$?.....|
000000b0 43 f7 e3 8b d1 86 d6 b1 06 d2 ee 42 f7 e2 39 56 |C..........B..9V|
000000c0 0a 77 23 72 05 39 46 08 73 1c b8 01 02 bb 00 7c |.w#r.9F.s......||
000000d0 8b 4e 02 8b 56 00 cd 13 73 51 4f 74 4e 32 e4 8a |.N..V...sQOtN2..|
000000e0 56 00 cd 13 eb e4 8a 56 00 60 bb aa 55 b4 41 cd |V......V.`..U.A.|
000000f0 13 72 36 81 fb 55 aa 75 30 f6 c1 01 74 2b 61 60 |.r6..U.u0...t+a`|
00000100 6a 00 6a 00 ff 76 0a ff 76 08 6a 00 68 00 7c 6a |j.j..v..v.j.h.|j|
00000110 01 6a 10 b4 42 8b f4 cd 13 61 61 73 0e 4f 74 0b |.j..B....aas.Ot.|
00000120 32 e4 8a 56 00 cd 13 eb d6 61 f9 c3 49 6e 76 61 |2..V.....a..Inva|
00000130 6c 69 64 20 70 61 72 74 69 74 69 6f 6e 20 74 61 |lid partition ta|
00000140 62 6c 65 00 45 72 72 6f 72 20 6c 6f 61 64 69 6e |ble.Error loadin|
00000150 67 20 6f 70 65 72 61 74 69 6e 67 20 73 79 73 74 |g operating syst|
00000160 65 6d 00 4d 69 73 73 69 6e 67 20 6f 70 65 72 61 |em.Missing opera|
00000170 74 69 6e 67 20 73 79 73 74 65 6d 00 00 00 00 00 |ting system.....|
00000180 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
000001b0 00 00 00 00 00 2c 44 63 9d 08 9e 08 00 00 00 01 |.....,Dc........|
000001c0 01 00 fd fe 3f 3c 3f 00 00 00 be f3 0e 00 00 00 |....?<?.........|
000001d0 01 3d fd fe ff ff fd f3 0e 00 e5 cb 40 0e 00 00 |.=..........@...|
000001e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.|
00000200 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00008200 20 be 03 00 80 79 07 00 ac 5f 00 00 11 b5 06 00 | ....y..._......|
00008210 01 be 03 00 01 00 00 00 00 00 00 00 00 00 00 00 |................|
00008220 00 20 00 00 00 20 00 00 f8 0f 00 00 31 9a 1d 48 |. ... ......1..H|
00008230 d0 9d 1d 48 01 00 1e 00 53 ef 01 00 01 00 00 00 |...H....S.......|
00008240 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 |................|
00008250 00 00 00 00 0b 00 00 00 80 00 00 00 00 00 00 00 |................|
00008260 02 00 00 00 01 00 00 00 d6 ce 40 e9 33 3a 4d 30 |..........@.3:M0|
00008270 8f 62 60 62 04 e9 34 24 62 6f 6f 74 00 00 00 00 |.b`b..4$boot....|
00008280 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00008600 04 00 00 00 05 00 00 00 06 00 00 00 00 00 e8 0f |................|
00008610 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008620 04 20 00 00 05 20 00 00 06 20 00 00 d2 10 f8 0f |. ... ... ......|
00008630 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008640 01 40 00 00 02 40 00 00 06 40 00 00 ff 1d f8 0f |.@...@...@......|
00008650 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008660 04 60 00 00 05 60 00 00 06 60 00 00 fc 1d f6 0f |.`...`...`......|
00008670 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008680 01 80 00 00 02 80 00 00 06 80 00 00 69 10 f8 0f |............i...|
00008690 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000086a0 04 a0 00 00 05 a0 00 00 06 a0 00 00 4b 0b f8 0f |............K...|
000086b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000086c0 01 c0 00 00 02 c0 00 00 06 c0 00 00 ff 1d f8 0f |................|
000086d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000086e0 04 e0 00 00 05 e0 00 00 06 e0 00 00 fc 1d f8 0f |................|
000086f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008700 01 00 01 00 02 00 01 00 06 00 01 00 ff 1d f8 0f |................|
00008710 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008720 04 20 01 00 05 20 01 00 06 20 01 00 fc 1d f8 0f |. ... ... ......|
00008730 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008740 01 40 01 00 02 40 01 00 06 40 01 00 ff 1d f8 0f |.@...@...@......|
00008750 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008760 01 60 01 00 02 60 01 00 06 60 01 00 ff 1d f8 0f |.`...`...`......|
00008770 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008780 01 80 01 00 02 80 01 00 06 80 01 00 ff 1d f8 0f |................|
00008790 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000087a0 01 a0 01 00 02 a0 01 00 06 a0 01 00 ff 1d f8 0f |................|
000087b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000087c0 01 c0 01 00 02 c0 01 00 06 c0 01 00 ff 1d f8 0f |................|
000087d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000087e0 01 e0 01 00 02 e0 01 00 06 e0 01 00 ff 1d f8 0f |................|
000087f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008800 01 00 02 00 02 00 02 00 06 00 02 00 ff 1d f8 0f |................|
00008810 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008820 01 20 02 00 02 20 02 00 06 20 02 00 ff 1d f8 0f |. ... ... ......|
00008830 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008840 01 40 02 00 02 40 02 00 06 40 02 00 ff 1d f8 0f |.@...@...@......|
00008850 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008860 01 60 02 00 02 60 02 00 06 60 02 00 ff 1d f8 0f |.`...`...`......|
00008870 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008880 01 80 02 00 02 80 02 00 06 80 02 00 ff 1d f8 0f |................|
00008890 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000088a0 01 a0 02 00 02 a0 02 00 06 a0 02 00 ff 1d f8 0f |................|
000088b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000088c0 01 c0 02 00 02 c0 02 00 06 c0 02 00 ff 1d f8 0f |................|
000088d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000088e0 01 e0 02 00 02 e0 02 00 06 e0 02 00 ff 1d f8 0f |................|
000088f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008900 01 00 03 00 02 00 03 00 06 00 03 00 ff 1d f8 0f |................|
00008910 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008920 04 20 03 00 05 20 03 00 06 20 03 00 fc 1d f8 0f |. ... ... ......|
00008930 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008940 01 40 03 00 02 40 03 00 06 40 03 00 55 1d eb 0f |.@...@...@..U...|
00008950 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008960 04 60 03 00 05 60 03 00 06 60 03 00 fc 1d f8 0f |.`...`...`......|
00008970 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008980 01 80 03 00 02 80 03 00 06 80 03 00 ff 1d f8 0f |................|
00008990 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000089a0 01 a0 03 00 02 a0 03 00 06 a0 03 00 ff 1d f8 0f |................|
000089b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000089c0 01 c0 03 00 02 c0 03 00 06 c0 03 00 ff 1d f8 0f |................|
000089d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000089e0 01 e0 03 00 02 e0 03 00 06 e0 03 00 ff 1d f8 0f |................|
000089f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008a00 01 00 04 00 02 00 04 00 06 00 04 00 ff 1d f8 0f |................|
00008a10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008a20 01 20 04 00 02 20 04 00 06 20 04 00 ff 1d f8 0f |. ... ... ......|
00008a30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008a40 01 40 04 00 02 40 04 00 06 40 04 00 ff 1d f8 0f |.@...@...@......|
00008a50 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008a60 01 60 04 00 02 60 04 00 06 60 04 00 ff 1d f8 0f |.`...`...`......|
00008a70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008a80 01 80 04 00 02 80 04 00 06 80 04 00 ff 1d f8 0f |................|
00008a90 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008aa0 01 a0 04 00 02 a0 04 00 06 a0 04 00 ff 1d f8 0f |................|
00008ab0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008ac0 01 c0 04 00 02 c0 04 00 06 c0 04 00 ff 1d f8 0f |................|
00008ad0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008ae0 01 e0 04 00 02 e0 04 00 06 e0 04 00 ff 1d f8 0f |................|
00008af0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008b00 01 00 05 00 02 00 05 00 06 00 05 00 ff 1d f8 0f |................|
00008b10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008b20 01 20 05 00 02 20 05 00 06 20 05 00 ff 1d f8 0f |. ... ... ......|
00008b30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008b40 01 40 05 00 02 40 05 00 06 40 05 00 ff 1d f8 0f |.@...@...@......|
00008b50 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008b60 01 60 05 00 02 60 05 00 06 60 05 00 ff 1d f8 0f |.`...`...`......|
00008b70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008b80 01 80 05 00 02 80 05 00 06 80 05 00 ff 1d f8 0f |................|
00008b90 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008ba0 01 a0 05 00 02 a0 05 00 06 a0 05 00 ff 1d f8 0f |................|
00008bb0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008bc0 01 c0 05 00 02 c0 05 00 06 c0 05 00 ff 1d f8 0f |................|
00008bd0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008be0 01 e0 05 00 02 e0 05 00 06 e0 05 00 ff 1d f8 0f |................|
00008bf0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008c00 01 00 06 00 02 00 06 00 06 00 06 00 ff 1d f8 0f |................|
00008c10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008c20 04 20 06 00 05 20 06 00 06 20 06 00 fc 1d f8 0f |. ... ... ......|
00008c30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008c40 01 40 06 00 02 40 06 00 06 40 06 00 ff 1d f8 0f |.@...@...@......|
00008c50 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008c60 01 60 06 00 02 60 06 00 06 60 06 00 ff 1d f8 0f |.`...`...`......|
00008c70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008c80 01 80 06 00 02 80 06 00 06 80 06 00 ff 1d f8 0f |................|
00008c90 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008ca0 01 a0 06 00 02 a0 06 00 06 a0 06 00 ff 1d f8 0f |................|
00008cb0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008cc0 01 c0 06 00 02 c0 06 00 06 c0 06 00 ff 1d f8 0f |................|
00008cd0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008ce0 01 e0 06 00 02 e0 06 00 06 e0 06 00 ff 1d f8 0f |................|
00008cf0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008d00 01 00 07 00 02 00 07 00 06 00 07 00 ff 1d f8 0f |................|
00008d10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008d20 01 20 07 00 02 20 07 00 06 20 07 00 ff 1d f8 0f |. ... ... ......|
00008d30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008d40 01 40 07 00 02 40 07 00 06 40 07 00 ff 1d f8 0f |.@...@...@......|
00008d50 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008d60 01 60 07 00 02 60 07 00 06 60 07 00 7e 17 f8 0f |.`...`...`..~...|
00008d70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00008d80 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
*
00009200 ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00009210 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00009680 ed 41 00 00 00 04 00 00 f7 42 04 48 a9 9d 1d 48 |.A.......B.H...H|
00009690 a9 9d 1d 48 00 00 00 00 00 00 04 00 02 00 00 00 |...H............|
000096a0 00 00 00 00 00 00 00 00 05 02 00 00 00 00 00 00 |................|
000096b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00009b00 ed 41 00 00 00 30 00 00 12 9a 1d 48 12 9a 1d 48 |.A...0.....H...H|
00009b10 12 9a 1d 48 00 00 00 00 00 00 02 00 18 00 00 00 |...H............|
00009b20 00 00 00 00 00 00 00 00 06 02 00 00 07 02 00 00 |................|
00009b30 08 02 00 00 09 02 00 00 0a 02 00 00 0b 02 00 00 |................|
00009b40 0c 02 00 00 0d 02 00 00 0e 02 00 00 0f 02 00 00 |................|
00009b50 10 02 00 00 11 02 00 00 00 00 00 00 00 00 00 00 |................|
00009b60 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00009b80 a4 81 00 00 78 0e 1d 00 ab 9a 1d 48 ab 9a 1d 48 |....x......H...H|
00009b90 95 45 fe 47 00 00 00 00 00 00 01 00 9a 0e 00 00 |.E.G............|
00009ba0 00 00 00 00 00 00 00 00 12 02 00 00 13 02 00 00 |................|
00009bb0 14 02 00 00 15 02 00 00 16 02 00 00 17 02 00 00 |................|
00009bc0 18 02 00 00 19 02 00 00 1a 02 00 00 1b 02 00 00 |................|
00009bd0 1c 02 00 00 1d 02 00 00 1e 02 00 00 1f 03 00 00 |................|
00009be0 00 00 00 00 d9 e9 41 20 00 00 00 00 00 00 00 00 |......A ........|
00009bf0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00009c00 a4 81 00 00 5c 38 01 00 ab 9a 1d 48 ab 9a 1d 48 |....\8.....H...H|
00009c10 95 45 fe 47 00 00 00 00 00 00 01 00 a0 00 00 00 |.E.G............|
00009c20 00 00 00 00 00 00 00 00 5f 09 00 00 60 09 00 00 |........_...`...|
128+0 records in
128+0 records out
65536 bytes (66 kB) copied, 0.0243211 s, 2.7 MB/s
00009c30 61 09 00 00 62 09 00 00 63 09 00 00 64 09 00 00 |a...b...c...d...|
00009c40 65 09 00 00 66 09 00 00 67 09 00 00 68 09 00 00 |e...f...g...h...|
00009c50 69 09 00 00 6a 09 00 00 6b 09 00 00 00 00 00 00 |i...j...k.......|
00009c60 00 00 00 00 da e9 41 20 00 00 00 00 00 00 00 00 |......A ........|
00009c70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00009c80 a4 81 00 00 cf 72 06 00 ab 9a 1d 48 ab 9a 1d 48 |.....r.....H...H|
00009c90 95 45 fe 47 00 00 00 00 00 00 01 00 40 03 00 00 |.E.G........@...|
00009ca0 00 00 00 00 00 00 00 00 af 09 00 00 b0 09 00 00 |................|
00009cb0 b1 09 00 00 b2 09 00 00 b3 09 00 00 b4 09 00 00 |................|
00009cc0 b5 09 00 00 b6 09 00 00 b7 09 00 00 b8 09 00 00 |................|
00009cd0 b9 09 00 00 ba 09 00 00 bb 09 00 00 bc 0a 00 00 |................|
00009ce0 00 00 00 00 db e9 41 20 00 00 00 00 00 00 00 00 |......A ........|
00009cf0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00009d00 a4 81 00 00 34 bb 0d 00 ab 9a 1d 48 ab 9a 1d 48 |....4......H...H|
00009d10 95 45 fe 47 00 00 00 00 00 00 01 00 e8 06 00 00 |.E.G............|
00009d20 00 00 00 00 00 00 00 00 4f 0b 00 00 50 0b 00 00 |........O...P...|
00009d30 51 0b 00 00 52 0b 00 00 53 0b 00 00 54 0b 00 00 |Q...R...S...T...|
00009d40 55 0b 00 00 56 0b 00 00 57 0b 00 00 58 0b 00 00 |U...V...W...X...|
00009d50 59 0b 00 00 5a 0b 00 00 5b 0b 00 00 5c 0c 00 00 |Y...Z...[...\...|
00009d60 00 00 00 00 dc e9 41 20 00 00 00 00 00 00 00 00 |......A ........|
00009d70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00009d80 a4 81 00 00 6b 1f 79 00 b5 9a 1d 48 c8 9a 1d 48 |....k.y....H...H|
00009d90 be 9a 1d 48 00 00 00 00 00 00 01 00 d0 3c 00 00 |...H.........<..|
00009da0 00 00 00 00 00 00 00 00 c3 0e 00 00 c4 0e 00 00 |................|
00009db0 c5 0e 00 00 c6 0e 00 00 c7 0e 00 00 c8 0e 00 00 |................|
00009dc0 c9 0e 00 00 ca 0e 00 00 cb 0e 00 00 cc 0e 00 00 |................|
00009dd0 cd 0e 00 00 ce 0e 00 00 cf 0e 00 00 d0 0f 00 00 |................|
00009de0 00 00 00 00 dd e9 41 20 00 00 00 00 00 00 00 00 |......A ........|
00009df0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00010000
cypr3ss@server1:~$
This volume isn't now, and has never been (as far as i can remember) a boot
volume.
I also did some more googling and found this, which (afaict) is just a
replication of the above, but thought it may help.
$ sudo hexdump -C /dev/sdc | head
00000000 33 c0 8e d0 bc 00 7c fb 50 07 50 1f fc be 1b 7c |3.....|.P.P....||
00000010 bf 1b 06 50 57 b9 e5 01 f3 a4 cb bd be 07 b1 04 |...PW...........|
00000020 38 6e 00 7c 09 75 13 83 c5 10 e2 f4 cd 18 8b f5 |8n.|.u..........|
00000030 83 c6 10 49 74 19 38 2c 74 f6 a0 b5 07 b4 07 8b |...It.8,t.......|
00000040 f0 ac 3c 00 74 fc bb 07 00 b4 0e cd 10 eb f2 88 |..<.t...........|
00000050 4e 10 e8 46 00 73 2a fe 46 10 80 7e 04 0b 74 0b |N..F.s*.F..~..t.|
00000060 80 7e 04 0c 74 05 a0 b6 07 75 d2 80 46 02 06 83 |.~..t....u..F...|
00000070 46 08 06 83 56 0a 00 e8 21 00 73 05 a0 b6 07 eb |F...V...!.s.....|
00000080 bc 81 3e fe 7d 55 aa 74 0b 80 7e 10 00 74 c8 a0 |..>.}U.t..~..t..|
00000090 b7 07 eb a9 8b fc 1e 57 8b f5 cb bf 05 00 8a 56 |.......W.......V|
I don't know what this output should look like when it's "correct", but I get
the feeling this isn't right.
Regards,
Stephen.
Stephen Porter wrote:
> Hello,
>
> Hoping someone may be able to offer some advice/assistance.
>
> I lost power twice (within a few hours) to my machine which had a ~2.2TB
> XFS volume on it. The first time the machine (running Xubuntu 8.04)
> came back up ok, the second time the XFS volume will not mount. Is
> there any chance of recovering the data? /dev/sdc is seen by xubuntu as
> one ~2.2TB disk, and I put the XFS file system straight onto the disk.
> It's 4x750GB drives on a hardware raid controller (rocketraid 2320).
> Driver/module for rocket raid (rr232x) is loaded ok.
hm, not an in-kernel driver, I guess?
> In the system log I see:
>
> XFS: bad magic number
>
> XFS: SB validate failed
>
> I tried running xfs_check, the result of this was:
>
> xfs_check /dev/sdc
> xfs_check: unexpected XFS SB magic number 0x33c08ed0
> xfs_check: size check failed
> xfs_check: read failed: Invalid argument
> xfs_check: data size check failed
> xfs_check: failed to alloc -225176656 bytes: Cannot allocate memory
>
> I looked at running xfs_repair, but the man page states that this will
> only work on a volume that has been unmounted cleanly... as I lost power
> the volume has not been unmounted cleanly, but I cannot mount it again
> to unmount it cleanly.
If you have to, you can zero the log w/ xfs_repair as a last resort.
> Running xfs_repair gives the following:
>
> xfs_repair -n /dev/sdc
>
> Phase 1 - find and verify superblock...
>
> bad primary superblock - bad magic number !!!
>
> ...attempting to find secondary superblock...
>
> ...found candidate secondary superblock... unable to verify superblock,
> continuing...
I always wished it said where, and why it did not verify....
> (the above appears a few times, until finally)
>
> ...Sorry, could not find valid secondary superblock
>
> Exiting now.
>
> I've seen it mentioned in other posts to the xfs archive to check that
> there is an xfs volume there, so I've also included the output of "dd
> if=/dev/sdc bs=512 count=1 iflag=direct 2> /dev/null | od -Ax -x" below:
>
> $ dd if=/dev/sdc bs=512 count=1 iflag=direct 2> /dev/null | od -Ax -x
>
> 000000 c033 d08e 00bc fb7c 0750 1f50 befc 7c1b
> 000010 1bbf 5006 b957 01e5 a4f3 bdcb 07be 04b1
Can you try piping it through "hexdump -C" instead, I'm more used to
eyeballing that output :)
You might also try looking a bit further:
dd if=/dev/sdc bs=512 count=128 iflag=direct | hexdump -C | grep XFSB
to see if maybe the raid card does something else at the front of your
disk and the superblock is further in, and something got scrambled up?
Just a longshot....
-Eric
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