[Techtalk] Partitioning issues.

[Travis Casey]

[Whoops... meant to send this to the list, not just to Elizabeth]

Friday, July 25, 2003, 5:50:39 AM, Elizabeth Barham wrote:
> Mary writes:

>> Assuming she recovers the data, there's nothing stopping her
>> attempting to partition again.

> But I mean since she re-partitioned it from what it was, stopped,
> realized her mistake, can she not simply reverse the changes to the
> partition table?

> Provided she does not alter the partition in anyway from what it was
> previously, it seems to me that the start address for each partition
> would go back to where it was. Since that area of the disk is already
> formatted with her old data, then the system would:

> 1) Read the partition information from the partition table at boot,
>    and
> 2) Check the same physical spot on the drive for the partition on
>    mount, which is the same as before.

> Provided fdisk does not alter the data on the physical partitions
> themselves but rather only alters the partition table on the drive,
> and provided that there is no timestamp or other type of state that
> cannot be re-created, then it sounds to me as though it would work but
> I have not tried it.

I've done that before on a machine which somehow lost partioning info
-- I'd just set it up the day before, so I still had the scrap of
paper where I'd worked out all the partition starts and ends.  This
was on a Trustix Linux system, using fdisk.  Once I re-entered the
partition table information, all was well.

I know that in the Windows world, there are utilities specifically for
backing up and restoring partition tables, since some viruses destroy
the partition table, but not the data on the disk.

A web search turned up gpart:

  http://www.stud.uni-hannover.de/user/76201/gpart/

According to the page, this is a program which will examine a hard
drive and see if it can "guess" what the partition table should have
looked like.  It can then write the guessed table to the drive.

Another utility which tries to do the same thing, and can be put on a
bootable DOS floppy and run:

  http://www.geocities.com/thestarman3/testdisk.html

-- 
Travis Casey
efindel at earthlink.net