[ILUG] partition problem

[Niall O Broin]

On Tue, Jul 10, 2001 at 09:04:08AM +0100, Lennon, Conor wrote:

> I have a hard which has a damaged partition table.
> There's a linux partition on the disk and I know where the partition begins
> and ends.
> I can do 
> 	dd if=/dev/hdb of=/tmp/disk skip=<start> count=<length>
> The problem is that the partition is around 2.4 gigs, and dd stops after 2
> gigs, as linux doesn't support files bigger than that.
> I can mount the incomplete output file in loop back mode, but obviously not
> all the files are there.
> Is there any way to access all the files?

Three suggestions:

1) The 2.4 kernel doesn't have the 2GB limitation, so bring the disk to a
2.4 machine, or bring a 2.4 kernel to the machine with the disk.

2) You know where the partition begins and ends, so why not just recreate
the partition table (of course, if the partition table area is defective,
this is a non-runner)

3) If you have another available sacrificial hard disk, say hdc, then make
two files from the damaged disk with

dd if=/dev/hdb of=/tmp/part1 skip=<start> count=<length/2> bs=100k
dd if=/dev/hdb of=/tmp/part2 skip=<start+length/2> count=<length/2> bs=100k

Then make a partition table on hdc which has a similarly sized partition and
do

dd of=/dev/hdc if=/tmp/part1 skip=<newstart> bs=100k
dd of=/dev/hdc if=/tmp/part2 skip=<newstart+length/2> bs=100k

I used the word sacrificial advisedly, because the potential for hard disk
chewing here is not low.


One of the above should help you. 2) is of course easiest, but I suspect
you'd have already have thought of that. 3) is of course the most
entertaining :-)



Regards,


Niall