[ale] Rebuild partition table

[Greg Freemyer]

Paul,

For full commentary read "help with LDE [linux disk editor]" from the
end of November.

Or the digest form is:
===
I'm pretty sure all gpart touches is the partition table in the MBR.
(The below assumes your old corrupted drive is /dev/hdc).

First save a copy of the MBR:
   dd if=/dev/hdc of=MBR-backup-file bs=512 count=1

Then have gpart recreate the partition table
   gpart -W /dev/hdc /dev/hdc

Then do a "fdisk -l /dev/hdc" and see if it looks right.

Then try to mount each of the partitions and see if they work.  I
normally do this read-only.

mount -r /dev/hdc1 /mnt
umount /mnt
etc.
===

Greg

On 1/22/07, Paul Borghese <pborghese at groupstudy.com> wrote:
> I have a dual-boot machine with two disk, one running Linux and the other
> Windows XP.
>
> Do to work requirements I needed to install a larger hard drive for my
> Windows XP partition.  I used the Maxblastor software to move my old
> Windows software to the new hard drive.  Everything went fine except for
> the Windows partition would not boot.  I beleive the Maxtor software was
> unable to handle the GRUB MBR.  So I found my Windows installation disk
> and performed a fixmbr and fixboot figuring I can always reboot using a
> Linux rescue disk to reinstall GRUB.
>
> There is a good chance I ended up running fixmbr and fixboot not just on
> the Windows disk but also my Linux drive.  The linux drive is now
> unbootable.  When I try to mound my linux partition using an Ubuntu live
> disk, I am told the partition does not exist.  Finally when I run fdisk, I
> receive the following output:
>
> --------------------------------------------------------------
> Command (m for help): p
>
> Disk /dev/sdc: 250.0 GB, 250059350016 bytes
> 255 heads, 63 sectors/track, 30401 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
>
> This doesn't look like a partition table
> Probably you selected the wrong device.
>
>    Device Boot      Start         End      Blocks   Id  System
> /dev/sdc1   ?      116388      126889    84344761   69  Unknown
> Partition 1 does not end on cylinder boundary.
> /dev/sdc2   ?      105915      222310   934940732+  73  Unknown
> Partition 2 does not end on cylinder boundary.
> /dev/sdc3   ?           1           1           0   74  Unknown
> Partition 3 does not end on cylinder boundary.
> /dev/sdc4               1      213826  1717556736    0  Empty
> Partition 4 does not end on cylinder boundary.
>
> Partition table entries are not in disk order
> ------------------------------------------------
>
> So it looks like in the process of restoring my Windows disk, I corrupted
> my  Linux disk partition table.  Any ideas on how to repair the partition
> table without loosing data?
>
> Thanks!
>
> Paul
>
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>


-- 
Greg Freemyer
The Norcross Group
Forensics for the 21st Century