On 09/22/2013 08:29 PM, Dave Gomboc wrote: > I now have the 4TB Hitachis in again. I'll leave them in unless you > ask me to switch back to the 2TB Seagates. Ok. >> dd if=/dev/sdX1 bs=4096 skip=1 count=1 2>/dev/null |hexdump -C >> dd if=/dev/sdX1 bs=4096 skip=2048 count=16 2>/dev/null |hexdump -C >> >> And reverify which drive name in linux corresponds to which serial number. > > ls -l /dev/disk/by-id output includes: > > lrwxrwxrwx 1 root root 9 Sep 22 17:20 > ata-Hitachi_HDS724040ALE640_PK1310PAG5ZY0J -> ../../sdb > lrwxrwxrwx 1 root root 10 Sep 22 17:20 > ata-Hitachi_HDS724040ALE640_PK1310PAG5ZY0J-part1 -> ../../sdb1 > lrwxrwxrwx 1 root root 9 Sep 22 17:20 > ata-Hitachi_HDS724040ALE640_PK1310PAG62REJ -> ../../sdc > lrwxrwxrwx 1 root root 10 Sep 22 17:20 > ata-Hitachi_HDS724040ALE640_PK1310PAG62REJ-part1 -> ../../sdc1 > lrwxrwxrwx 1 root root 9 Sep 22 17:20 > ata-Hitachi_HDS724040ALE640_PK1310PAG62T2J -> ../../sdd > lrwxrwxrwx 1 root root 10 Sep 22 17:20 > ata-Hitachi_HDS724040ALE640_PK1310PAG62T2J-part1 -> ../../sdd1 > lrwxrwxrwx 1 root root 9 Sep 22 17:20 > ata-Hitachi_HDS724040ALE640_PK1311PAG4W5TS -> ../../sda > lrwxrwxrwx 1 root root 10 Sep 22 17:20 > ata-Hitachi_HDS724040ALE640_PK1311PAG4W5TS-part1 -> ../../sda1 Ok. > root@sysresccd /root % dd if=/dev/sda1 bs=4096 skip=1 count=1 > 2>/dev/null |hexdump -C > 00000000 fc 4e 2b a9 01 00 00 00 00 00 00 00 00 00 00 00 |.N+.............| > 00000010 3c 76 af 95 fa 16 ca 54 33 0b 75 47 b9 04 0b 8a |<v.....T3.uG....| > 00000020 63 68 65 61 70 3a 74 65 72 61 6d 6f 6f 63 68 00 |cheap:teramooch.| > 00000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > 00000040 df 62 21 4d 00 00 00 00 0a 00 00 00 02 01 00 00 |.b!M............| > 00000050 00 68 e0 e8 00 00 00 00 00 04 00 00 04 00 00 00 |.h..............| > 00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > * > 00000080 00 08 00 00 00 00 00 00 82 6c e0 e8 00 00 00 00 |.........l......| > 00000090 08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > 000000a0 00 00 00 00 00 00 00 00 66 80 69 13 40 2f 8c fb |........f.i.@/..| > 000000b0 a7 4e 11 fd 5c a1 7f ee 00 00 00 00 00 00 00 00 |.N..\...........| > 000000c0 b5 fe 33 52 00 00 00 00 08 02 00 00 00 00 00 00 |..3R............| > 000000d0 ff ff ff ff ff ff ff ff 7f 39 b7 06 80 01 00 00 |.........9......| > 000000e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > * > 00000100 00 00 01 00 02 00 03 00 fe ff fe ff fe ff fe ff |................| > 00000110 fe ff fe ff fe ff fe ff fe ff fe ff fe ff fe ff |................| > * > 00000400 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > * > 00001000 > root@sysresccd /root % dd if=/dev/sda1 bs=4096 skip=2048 count=16 > 2>/dev/null |hexdump -C > 00000000 73 65 74 0d 0a 20 20 20 62 20 20 20 20 20 20 20 |set.. b | Oops. Should have dropped the "bs=4096" on that one. The default "bs=512" is what I was trying for there. However, based on the data you've reported, sda1 and sdc1 are identical, down to the superblock bytes. And sdb1 and sdd1 are also identical, down to the superblock bytes. Are you sure there were no misdirected "dd" operations? Phil -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html