Corrupted Partition Table?

  • Thread starter Thread starter nadircruise
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nadircruise

I tried to install Kubuntu 6.06 on my system, but the installer was
unable to read the partition table for my hard drive. I did fdisk to
find out that my 55GB partition (hdb7) turned into a 31Kb partition.
Here is the output of fdisk:
Disk /dev/hdb: 80.0 GB, 80060424192 bytes
255 heads, 63 sectors/track, 9733 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/hdb1 * 1 1095 8795556 83 Linux
/dev/hdb2 1096 1146 409657+ 82 Linux swap /
Solaris
/dev/hdb3 1147 2648 12064815 5 Extended
/dev/hdb5 1648 2648 8040501 83 Linux
/dev/hdb6 1147 1647 4024219+ 83 Linux
/dev/hdb7 1648 1648 31 83 Linux

Partition table entries are not in disk order


I also did the following:

$ dmesg | tail
[ 9199.252441] EXT3-fs: mounted filesystem with ordered data mode.
[ 9598.353573] EXT3-fs: mounted filesystem with ordered data mode.
[ 9598.452241] kjournald starting. Commit interval 5 seconds
[ 9601.294008] kjournald starting. Commit interval 5 seconds
[ 9601.294984] EXT3 FS on hdb1, internal journal
[ 9601.295205] EXT3-fs: recovery complete.
[ 9601.295397] EXT3-fs: mounted filesystem with ordered data mode.
[ 9904.223672] SQUASHFS error: Can't find a SQUASHFS superblock on hdb7
[ 9932.247583] VFS: Can't find ext3 filesystem on dev hdb7.
[ 9946.863511] VFS: Can't find an ext2 filesystem on dev hdb7.

I hope someone would suggest me a way to recover my data on this
partition.

TIA

--Nadir
 
I tried to install Kubuntu 6.06 on my system, but the installer was
unable to read the partition table for my hard drive. I did fdisk to
find out that my 55GB partition (hdb7) turned into a 31Kb partition.
Here is the output of fdisk:
Disk /dev/hdb: 80.0 GB, 80060424192 bytes
255 heads, 63 sectors/track, 9733 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/hdb1 * 1 1095 8795556 83 Linux
/dev/hdb2 1096 1146 409657+ 82 Linux swap /
Solaris
/dev/hdb3 1147 2648 12064815 5 Extended
/dev/hdb5 1648 2648 8040501 83 Linux ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/dev/hdb6 1147 1647 4024219+ 83 Linux
/dev/hdb7 1648 1648 31 83 Linux ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^[...]

I hope someone would suggest me a way to recover my data on this
partition.
Click to expand...
Looks like that /dev/hdb5 overlaps /dev/hdb7.
But there seems to be lots of unused space behind cylinder 2648.
If hdb7 occupied that space before a partition recovery tool like testdisk
or gpart may help you to recover your old partition scheme.
 
In comp.sys.ibm.pc.hardware.storage Markus Kossmann said:
(e-mail address removed) wrote:
I tried to install Kubuntu 6.06 on my system, but the installer was
unable to read the partition table for my hard drive. I did fdisk to
find out that my 55GB partition (hdb7) turned into a 31Kb partition.
Here is the output of fdisk:
Disk /dev/hdb: 80.0 GB, 80060424192 bytes
255 heads, 63 sectors/track, 9733 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/hdb1 * 1 1095 8795556 83 Linux
/dev/hdb2 1096 1146 409657+ 82 Linux swap /
Solaris
/dev/hdb3 1147 2648 12064815 5 Extended
/dev/hdb5 1648 2648 8040501 83 Linux ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/dev/hdb6 1147 1647 4024219+ 83 Linux
/dev/hdb7 1648 1648 31 83 Linux ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^[...]

I hope someone would suggest me a way to recover my data on this
partition.
Click to expand...
Looks like that /dev/hdb5 overlaps /dev/hdb7.
But there seems to be lots of unused space behind cylinder 2648.
If hdb7 occupied that space before a partition recovery tool like testdisk
or gpart may help you to recover your old partition scheme.
Click to expand...

Acttually there does not have to be overlap. I the partitions are
not cylinder-alogned, then there may just have been space for
the very small partition. My guess is that the Kubuntu installer
deleted the original hdb7 and created a new one in the first space
available. The original hdb7 should still be there somewere after
cylinder 2648. You might be able to re-create it using parted's
''rescue'' command.

Side note: Don't do an OS installation without a current backup!

Arno
 
I tried to install Kubuntu 6.06 on my system, but the installer was unable
to read the partition table for my hard drive. I did fdisk to find out
that my 55GB partition (hdb7) turned into a 31Kb partition. Here is the
output of fdisk:
Disk /dev/hdb: 80.0 GB, 80060424192 bytes 255 heads, 63 sectors/track,
9733 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
Click to expand...
/dev/hdb1 * 1 1095 8795556 83 Linux
/dev/hdb2 1096 1146 409657+ 82 Linux swap /Solaris
/dev/hdb3 1147 2648 12815064 5 Extended

/dev/hdb6 1147 1647 4024219+ 83 Linux
/dev/hdb7 1648 1648 31 83 Linux
/dev/hdb5 1648 2648 8040501 83 Linux
Partition table entries are not in disk order


I also did the following:

$ dmesg | tail
[ 9199.252441] EXT3-fs: mounted filesystem with ordered data mode. [
9598.353573] EXT3-fs: mounted filesystem with ordered data mode. [
9598.452241] kjournald starting. Commit interval 5 seconds [
9601.294008] kjournald starting. Commit interval 5 seconds [
9601.294984] EXT3 FS on hdb1, internal journal [ 9601.295205] EXT3-fs:
recovery complete. [ 9601.295397] EXT3-fs: mounted filesystem with
ordered data mode. [ 9904.223672] SQUASHFS error: Can't find a SQUASHFS
superblock on hdb7 [ 9932.247583] VFS: Can't find ext3 filesystem on dev
hdb7. [ 9946.863511] VFS: Can't find an ext2 filesystem on dev hdb7.

I hope someone would suggest me a way to recover my data on this
partition.

TIA

--Nadir
Click to expand...

I think it's too late for /dev/hb7 the partition is set.
Mounting a boot CD for the existing Linux system, booting to
linux rescue mode, then mounting /dev/hdb7 as an ext2 filesystem, ie,
mount -t ext2 would have allowed you to take a look at what you have. But
Dmesg says it can't find a Ext2 fs either.

Is this a complete fdisk report? The /dev/hdb5 that looks like
the remainder of a 12G extended partition. IMO, you still have
55G around just not part of /dev/hdb3, because totals don't add up to 80Gb.

I think /dev/hdb7 is left over from something but you haven't allocated
the remaining 55G as part of the extended partition.

/dev/hdb7 should've started af 2649 not 1648. For your 80Gb
/dev/hdb7 should look something like start 2649 / end 9733 or better
/dev/hbb3 start 1143 / end 9733 67815604 5 Extended.

Maybe you should try the Gparted LiveCD, for a non-destructive resize
of the Hd. Or MbtTool to change the partition attributes and size or at
least take a better look at what's been done.
 
I tried to install Kubuntu 6.06 on my system, but the installer was
unable to read the partition table for my hard drive. I did fdisk to
find out that my 55GB partition (hdb7) turned into a 31Kb partition.
Here is the output of fdisk:
Disk /dev/hdb: 80.0 GB, 80060424192 bytes
255 heads, 63 sectors/track, 9733 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Click to expand...

I had a similar problem and was able to sort it out. I don't recall the
name of the utility I used, but I was thinking it was something like
'testdisk' - pretty sketchy, I know, but hope that helps. I've also had
good experience with the gparted Live CD.
 
Is this a complete fdisk report? The /dev/hdb5 that looks like
the remainder of a 12G extended partition. IMO, you still have
55G around just not part of /dev/hdb3, because totals don't add up to 80Gb.
Click to expand...

Yes i think this is the complete fdisk report. Actually hdb7 was
supposed to be a part of the extended partition. it was something like
:
hdb1 was 8GB, hdb2 was .5GB (swap), and there was an extended partition
which contained hdb5 and hdb6 which were 12 GB (4+8), and the rest was
given to hdb7. Now since fdisk doesn't show any free space, and hdb7
partition only has 31Kb, that made me feel that somehow the partition
table is corrupted. Anyway thanks for helping!

I think /dev/hdb7 is left over from something but you haven't allocated
the remaining 55G as part of the extended partition.

/dev/hdb7 should've started af 2649 not 1648. For your 80Gb
/dev/hdb7 should look something like start 2649 / end 9733 or better
/dev/hbb3 start 1143 / end 9733 67815604 5 Extended.

Maybe you should try the Gparted LiveCD, for a non-destructive resize
of the Hd. Or MbtTool to change the partition attributes and size or at
least take a better look at what's been done.
Click to expand...

Will try gparted, and let you know if it gets fixed!
Thanks once again!
--Nadir
 
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