The drive looks like it was spinning at normal speed while power was supplied to the disk via the USB interface. The spec for most drives is +- 1% of the nominal spin speed is acceptable. The drive lost power while reading and writing so it may have queered your partition table area - the very first 512 bytes of the drive.
So checking /proc/partitions
is useful. cat /proc/partitions
dmesg
should report the last drive letter being acquired by the kernel eg. b or c or d. Use fdisk -l /dev/sdX
where X is a b or c or d. If it reports a problem you can probably re-create the partition table using parted
gparted
or fdisk
.
The trick is to examine the possible partitions - offset and type
To save your data - you need to run a dd
command and copy the complete disk image
from /dev/sdX
to a file on a much larger disk partition - mounted as /home
maybe.
dd if=/dev/sdc of=/home/sdc.dd conv=noerror,sync
It will take a while - maybe a day and most of the night for large Gigabyte drives.
Then you can play with the drive itself - recreate a filesystem etc.
The biggest test that dd
will provide is the integrity of the drive while just
reading blocks.
Similar to a fsck -t ext3 -c
command which should check for bad-blocks on a drive.
If the dd
command fails it should provide a bit of info on where on the drive it fought
bad sector errors.
If the drive reports errors early on - that may explain the loss of partition info.
I often do a od -cx /dev/sdX | less
to check the possible offsets
to make things easy some od
commands take options for convenience
eg. od -cx -Ad /dev/sdX | less
0000000 353 H 220 020 216 320 274 \0 260 270 \0 \0 216 330 216 300
48eb 1090 d08e 00bc b8b0 0000 d88e c08e
0000016 373 276 \0 | 277 \0 006 271 \0 002 363 244 352 ! 006 \0
befb 7c00 00bf b906 0200 a4f3 21ea 0006
0000032 \0 276 276 \a 8 004 u \v 203 306 020 201 376 376 \a u
be00 07be 0438 0b75 c683 8110 fefe 7507
0000048 363 353 026 264 002 260 001 273 \0 | 262 200 212 t 003 002
ebf3 b416 b002 bb01 7c00 80b2 748a 0203
0000064 200 \0 \0 200 E 202 \r \0 \0 \b 372 220 220 366 302 200
0080 8000 8245 000d 0800 90fa f690 80c2
0000080 u 002 262 200 352 Y | \0 \0 1 300 216 330 216 320 274
0275 80b2 59ea 007c 3100 8ec0 8ed8 bcd0
0000096 \0 373 240 @ | < 377 t 002 210 302 R 276 177 }
2000 a0fb 7c40 ff3c 0274 c288 be52 7d7f
0000112 350 4 001 366 302 200 t T 264 A 273 252 U 315 023 Z
34e8 f601 80c2 5474 41b4 aabb cd55 5a13
0000128 R r I 201 373 U 252 u C 240 A | 204 300 u 005
7252 8149 55fb 75aa a043 7c41 c084 0575
0000144 203 341 001 t 7 f 213 L 020 276 005 | 306 D 377 001
e183 7401 6637 4c8b be10 7c05 44c6 01ff
0000160 f 213 036 D | 307 004 020 \0 307 D 002 001 \0 f 211
8b66 441e c77c 1004 c700 0244 0001 8966
0000176 \ \b 307 D 006 \0 p f 1 300 211 D 004 f 211 D
085c 44c7 0006 6670 c031 4489 6604 4489
0000192 \f 264 B 315 023 r 005 273 \0 p 353 } 264 \b 315 023
b40c cd42 7213 bb05 7000 7deb 08b4 13cd
0000208 s \n 366 302 200 017 204 352 \0 351 215 \0 276 005 | 306
0a73 c2f6 0f80 ea84 e900 008d 05be c67c
0000224 D 377 \0 f 1 300 210 360 @ f 211 D 004 1 322 210
ff44 6600 c031 f088 6640 4489 3104 88d2
0000240 312 301 342 002 210 350 210 364 @ 211 D \b 1 300 210 320
c1ca 02e2 e888 f488 8940 0844 c031 d088
0000256 300 350 002 f 211 004 f 241 D | f 1 322 f 367 4
e8c0 6602 0489 a166 7c44 3166 66d2 34f7
0000272 210 T \n f 1 322 f 367 t 004 210 T \v 211 D \f
5488 660a d231 f766 0474 5488 890b 0c44
0000288 ; D \b } < 212 T \r 300 342 006 212 L \n 376 301
443b 7d08 8a3c 0d54 e2c0 8a06 0a4c c1fe
0000304 \b 321 212 l \f Z 212 t \v 273 \0 p 216 303 1 333
d108 6c8a 5a0c 748a bb0b 7000 c38e db31
0000320 270 001 002 315 023 r * 214 303 216 006 H | ` 036 271
01b8 cd02 7213 8c2a 8ec3 4806 607c b91e
0000336 \0 001 216 333 1 366 1 377 374 363 245 037 a 377 & B
0100 db8e f631 ff31 f3fc 1fa5 ff61 4226
0000352 | 276 205 } 350 @ \0 353 016 276 212 } 350 8 \0 353
be7c 7d85 40e8 eb00 be0e 7d8a 38e8 eb00
0000368 006 276 224 } 350 0 \0 276 231 } 350 * \0 353 376 G
be06 7d94 30e8 be00 7d99 2ae8 eb00 47fe
0000384 R U B \0 G e o m \0 H a r d D
5552 2042 4700 6f65 006d 6148 6472 4420
0000400 i s k \0 R e a d \0 E r r o r \0
7369 006b 6552 6461 2000 7245 6f72 0072
0000416 273 001 \0 264 016 315 020 254 < \0 u 364 303 \0 \0 \0
01bb b400 cd0e ac10 003c f475 00c3 0000
0000432 \0 \0 \0 \0 \0 \0 \0 \0 S 005 \v \0 \0 \0 200 001
0000 0000 0000 0000 0553 000b 0000 0180
0000448 001 \0 203 376 ? > ? \0 \0 \0 @ q 017 \0 \0 \0
0001 fe83 3e3f 003f 0000 7140 000f 0000
0000464 001 ? 203 376 377 377 177 q 017 \0 276 275 q 022 \0 376
3f01 fe83 ffff 717f 000f bdbe 1271 fe00
0000480 377 377 202 376 377 377 = / 201 022 002 336 037 \0 \0 \0
ffff fe82 ffff 2f3d 1281 de02 001f 0000
0000496 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 U 252
0000 0000 0000 0000 0000 0000 0000 aa55
0000512 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0
0000 0000 0000 0000 0000 0000 0000 0000
*
0001024 352 317 202 \0 \0 \0 004 \0 204 > \0 \0 X t \0 \0
cfea 0082 0000 0004 3e84 0000 7458 0000
0001040 \b X \0 \0 001 \0 \0 \0 377 377 377 377 / b o o
5808 0000 0001 0000 ffff ffff 622f 6f6f
0001056 t / g r u b \0 \0 \0 \0 \0 \0 \0 \0 \0 \0
2f74 7267 6275 0000 0000 0000 0000 0000
0001072 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0
0000 0000 0000 0000 0000 0000 0000 0000
*
0001104 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 002 260 255 033
0000 0000 0000 0000 0000 0000 b002 1bad
0001120 \0 \0 001 \0 376 O Q 344 \ 002 020 \0 \0 \0 020 \0
0000 0001 4ffe e451 025c 0010 0000 0010
0001136 \0 \0 \0 \0 \0 \0 \0 \0 | 002 020 \0 213 S \f 275
0000 0000 0000 0000 027c 0010 538b bd0c
0001152 360 377 \a \0 211 354 271 L \b \0 \0 003 \r 020 002 020
fff0 0007 ec89 4cb9 0008 0300 100d 1002
0001168 \0 276 \0 \0 020 \0 277 \0 200 \0 \0 374 363 244 270 245
be00 0000 0010 00bf 0080 fc00 a4f3 a5b8
0001184 202 \0 \0 377 340 211 320 301 350 \b 1 333 200 374 377 t
0082 ff00 89e0 c1d0 08e8 db31 fc80 74ff
0001200 \b 210 343 211 035 024 202 \0 \0 < 377 t \b 210 303 211
8808 89e3 141d 0082 3c00 74ff 8808 89c3
NOTE the *
on the left hand side
They indicate a lot more null or zero byte values
so my offset for a partition appears to be 1024 bytes into the drive.
which is 2 x 512 byte sectors or 1 x 1024 byte sectors
Given that most drives will probably look like this
root@rhbeta:/home/chrthomp # fdisk -l /dev/sdX
Disk /dev/sdX: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 63 506016 83 Linux
/dev/sda2 64 19325 154722015 83 Linux
/dev/sda3 19326 19455 1044225 82 Linux swap / Solaris
root@rhbeta:/home/chrthomp #
My drive appears to have a partition start at 1 and end at 63, which is usually a small /boot
ext2 partition. The 64 to 19325 area is a LVM file system apparently. Then comes the swap area. So since you have a backup - try to fix the problem by partitioning the drive.
fdisk /dev/sdX
create a 'n' partition '1' starting at '1' and ending at '63'
and then 'w' write the partition table.
that appears to be a reasonably safe bet. Run the following commands
file -s /dev/sdX1
fsck -t ext2 /dev/sdX1
mount -t ext2 /dev/sdX1 /mnt
/mnt
on a CDROM that boots is most probably available - you may have to mkdir /mnt/sdX1
and try mount -t ext2 /dev/sdX1 /mnt/sdX1
The other reason things may screw up is that the drive has been made
unstable - the electronics may never recover - particularly if its an old drive.
I've seen these pop up, have trouble and die and disappear - only to reappear
again in a loop.
Some people see this when /sbin/fsck.ntfs
is not installed.
the dmesg
and /var/log/messages
file will complain that the fsck.ntfs
does
not exist.
dmesg
,lsusb
, and an attempt to mount it manuallymount /dev/sdc /media/drive
, would help you get your answer.dmesg
gives me a lot of output (973 lines, 65343 bytes). If you want me to upload it to some site so you can look at it I can, though.lsusb
seems to recognize the device (Bus 002 Device 003: ID 03f0:3207 Hewlett-Packard
).sudo mount /dev/sdc /media/drive
gives memount: you must specify the filesystem type
. If I use-t vfat
, it gives memount: /dev/sdc: can't read superblock
, and-t ext4
givesmount: wrong fs type, bad option, bad superblock on /dev/sdc, missing codepage or helper program, or other error