I still got no answer for my problem thats why I try it here... hopefully you could help me out. System: Embedded board with Atmel SAM9x25 Debian Wheezy Kernel 3.11.6 32GB Samsung SDHC card with ext4 root- partition (journal activated) After system running two weeks or so superblock from rootfs (ext4) at block 0 got overwritten with "trash data". This is happening with like 20% of the embedded devices. hex comparision between faulty and good superblock starting at byte 1024: Before (good): 00000000 00 ee 02 00 00 b8 0b 00 00 96 00 00 ab a9 05 00 |................| 00000010 c3 0c 02 00 00 00 00 00 02 00 00 00 02 00 00 00 |................| 00000020 00 80 00 00 00 80 00 00 40 1f 00 00 9e 68 46 58 |........@....hFX| 00000030 9e 68 46 58 2e 00 64 00 53 ef 01 00 01 00 00 00 |.hFX..d.S.......| 00000040 0f 35 ff 55 00 00 00 00 00 00 00 00 01 00 00 00 |.5.U............| 00000050 00 00 00 00 0b 00 00 00 00 01 00 00 3c 00 00 00 |............<...| 00000060 46 02 00 00 7b 00 00 00 3b 9e 9c 82 4d 90 4d ed |F...{...;...M.M.| 00000070 84 41 3a 05 5c 37 fb a8 72 6f 6f 74 66 73 00 00 |.A:.\7..rootfs..| 00000080 00 00 00 00 00 00 00 00 2f 6d 65 64 69 61 2f 76 |......../media/v| 00000090 69 72 74 75 61 6c 73 69 67 69 2f 72 6f 6f 74 66 |irtualsigi/rootf| 000000a0 73 00 73 00 00 00 00 00 00 00 00 00 00 00 00 00 |s.s.............| 000000b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 000000c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 bb 00 |................| 000000d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 000000e0 08 00 00 00 00 00 00 00 00 00 00 00 41 41 7f 29 |............AA.)| 000000f0 b2 43 48 94 ab 07 f8 fa 38 1c 2e 33 01 01 00 00 |.CH.....8..3....| 00000100 0c 00 00 00 00 00 00 00 b8 40 6a 52 0a f3 01 00 |.........@jR....| 00000110 04 00 00 00 00 00 00 00 00 00 00 00 00 40 00 00 |.............@..| 00000120 00 00 05 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000130 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000140 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 04 |................| 00000150 00 00 00 00 00 00 00 00 00 00 00 00 1c 00 1c 00 |................| 00000160 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000170 00 00 00 00 04 00 00 00 cd 8a 94 00 00 00 00 00 |................| 00000180 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| After (corrupted): 00000000 00 00 00 00 a4 81 00 00 dd 00 00 00 24 8e 5d 54 |............$.]T| 00000010 7e 8e 5d 54 18 a6 9f 41 00 00 00 00 00 00 01 00 |~.]T...A........| 00000020 08 00 00 00 00 00 08 00 01 00 00 00 0a f3 01 00 |................| 00000030 04 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 |................| 00000040 54 b2 01 00 00 00 00 00 00 00 00 00 00 00 00 00 |T...............| 00000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000060 00 00 00 00 00 00 00 00 86 2a 63 08 00 00 00 00 |.........*c.....| 00000070 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000080 00 00 00 00 1c 00 00 00 60 c9 e6 31 00 00 00 00 |........`..1....| 00000090 00 00 00 00 7c 8e 5d 54 9c b0 2a ec 00 00 00 00 |....|.]T..*.....| 000000a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000100 00 00 00 00 a4 81 00 00 0f 00 00 00 67 4d 6b 52 |............gMkR| 00000110 67 4d 6b 52 63 87 84 4f 00 00 00 00 00 00 01 00 |gMkRc..O........| 00000120 08 00 00 00 00 00 08 00 01 00 00 00 0a f3 01 00 |................| 00000130 04 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 |................| 00000140 74 07 03 00 00 00 00 00 00 00 00 00 00 00 00 00 |t...............| 00000150 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000160 00 00 00 00 00 00 00 00 19 1e 79 cd 00 00 00 00 |..........y.....| 00000170 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000180 00 00 00 00 1c 00 00 00 e4 14 dc e7 00 00 00 00 |................| 00000190 98 6a 83 72 67 4d 6b 52 98 6a 83 72 00 00 00 00 |.j.rgMkR.j.r....| 000001a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000200 00 00 00 00 a4 81 00 00 88 0c 00 00 44 8c 5d 54 |............D.]T| 00000210 4d 8c 5d 54 9c 8e 52 54 00 00 00 00 00 00 01 00 |M.]T..RT........| 00000220 08 00 00 00 00 00 08 00 01 00 00 00 0a f3 01 00 |................| 00000230 04 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 |................| 00000240 7b e0 01 00 00 00 00 00 00 00 00 00 00 00 00 00 |{...............| 00000250 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000260 00 00 00 00 00 00 00 00 4e 09 63 08 00 00 00 00 |........N.c.....| 00000270 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000280 00 00 00 00 1c 00 00 00 f8 b4 6f 14 00 00 00 00 |..........o.....| 00000290 00 00 00 00 48 8c 5d 54 28 cc 55 82 00 00 00 00 |....H.]T(.U.....| 000002a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000300 00 00 00 00 a4 81 00 00 94 05 00 00 68 4d 6b 52 |............hMkR| 00000310 69 4d 6b 52 54 0f df 4f 00 00 00 00 00 00 01 00 |iMkRT..O........| 00000320 08 00 00 00 00 00 08 00 01 00 00 00 0a f3 01 00 |................| 00000330 04 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 |................| 00000340 8c 07 03 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000350 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000360 00 00 00 00 00 00 00 00 27 1e 79 cd 00 00 00 00 |........'.y.....| 00000370 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000380 00 00 00 00 1c 00 00 00 b0 07 a2 3a 00 00 00 00 |...........:....| 00000390 04 a9 de 29 68 4d 6b 52 04 a9 de 29 00 00 00 00 |...)hMkR...)....| 000003a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| - How is it possible, that even the magic number (and everything else) got overwritten? - Why could it ever be overwritten? Thank you so much! -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html