Re: [Bug-ddrescue] Recover a single NTFS partition off a damaged disk using ddrescue

[Ariel]

On Fri, 28 Jul 2006, Sanjay Rana wrote:

> Is it possible to recover a single NTFS partition as a disk image onto a 
> different hard disk using ddrescue?

> If so then what arguments will have to be used to do that and will it be 
> possible to retrieve the data from the disk image?

> My hard disk has lots of bad sectors in other partitions and I am unable to 
> overwrite the partition table. Mirroring the entire disk is also taking a lot 
> longer as well.

> I know the start and end of the partition in terms of the 
> cylinders,head,sector as reported by testdisk. Can this information be 
> useful?

What you will need to do is create a partition on the good disk that 
exactly matches the size (in sectors!) of the old one. It is very 
important that the sector size matches.

(Easiest way to do this, is partition the new hard disk using the same 
heads and sectors per track as the old one. You can only do this in linux, 
windows doesn't let you choose these numbers (although you might get lucky 
and they'll be the same anyway). Then create a partition with the same 
number of cylinders as the old one.)

Then use ddrescue to recover to that partition.

You could use a disk image, rather then a partition, but windows will not 
be able to use it, only linux. I think windows has better tools for 
recovering corrupted NTFS file systems, so I suggest a partition.

Actually - you could maybe use vmware, with a disk image. It will trick 
windows into thinking it's a normal partition on a hard disk. It's a 
little complex, but probably doable.

BTW: If you get anything useful from that partition, I suggest copying all 
the data off of it, to a new area. Don't keep the partition afterward, 
since it was the result of a corrupted NTFS, rather then a good format.

Basically you will need double the amount of space of the bad partition.

Hope this helps.

        -Ariel