[comp.sys.ibm.pc] Recover from FDISK?

boyer@iuvax.cs.indiana.edu (08/13/89)

Help!  I accidentally did an FDISK (re-partitioned) my disk drive.
I was attempting to partition another drive, but the computer did 
not recognize the other drive and re-partitioned a drive with data.

Is there any way to recover the data from this drive?

Thanks ahead,

Dave Boyer

cpcahil@virtech.UUCP (Conor P. Cahill) (08/13/89)

In article <36300057@iuvax>, boyer@iuvax.cs.indiana.edu writes:
> Help!  I accidentally did an FDISK (re-partitioned) my disk drive.
> I was attempting to partition another drive, but the computer did 
> not recognize the other drive and re-partitioned a drive with data.
> 
> Is there any way to recover the data from this drive?

Yes, all you have to do is re-fdisk the disk back to what it was originally.
Fdisk does not modify anything but the partition table, so as long as you
didn't format the drive, just re-fdisk the drive and set up the partitions
exactly as you had them before they were trashed.

If you have formatted the drive, I would tell you to get out your latest
set of backups (what, you haven't backed up the system since jan?).  The 
latest version of Norton Utilities is supposed to have a program that will
assist in the restoration of data on a formatted hard drive, but I have no
idea as to it's usefullness.

Good Luck

boyer@iuvax.cs.indiana.edu (08/14/89)

cpcahil@virtech.UUCP writes:
>Yes, all you have to do is re-fdisk the disk back to what it was originally.
>Fdisk does not modify anything but the partition table, so as long as you
>didn't format the drive, just re-fdisk the drive and set up the partitions
>exactly as you had them before they were trashed.

Sorry, I don't think that will work.  In fact, the disk was accidentally
partitioned to the same partition that originally existed.  And the data
that was once there is inaccessible. It seems to me, after looking around
with Norton, that the FAT has been erased.  Is it possible that FDISK does 
this?  All of the data is still there.

Dave

cpcahil@virtech.UUCP (Conor P. Cahill) (08/14/89)

In article <36300058@iuvax>, boyer@iuvax.cs.indiana.edu writes:
> Sorry, I don't think that will work.  In fact, the disk was accidentally
> partitioned to the same partition that originally existed.  And the data
> that was once there is inaccessible. It seems to me, after looking around
> with Norton, that the FAT has been erased.  Is it possible that FDISK does 
> this?  All of the data is still there.
> 
> Dave

Fdisk shouldn't modify anything other than the partition table.  At least
the fdisk that came with MS-DOS 2.11 did not.  On that OS I fdisked the
system to delete the dos partition and tried to boot the unix system boot
disk.  The unix system would not boot, so I re-fdisked back in my dos
partition expecting to have to restore all the data, but lo and behold
everything was as it should be.  I haven't tried this on 3.3, nor 4.01 
because who wants to try something that may destroy the system.

Anyway, fdisk should only modify the partition table.  It is not (or should
not be) smart enough to do anything else because that is the job of format.

If you're fat has been erased, it sounds like the disk was formatted. 
Norton 4.5 does have a utility that is supposed to help you in this kind of
situation, but I have never used it and don't know how well it works.

Good luck

wek@point.UUCP (Bill Kuykendall) (08/15/89)

It seems to me that this must vary with the version of 'DOS.  Compaq DOS
3.31 most definitely reinitializes the FAT when fdisk is run.  On the other
hand, I'm certain that I've recovered hard disks that had been fdisk'ed in
the past.  

bobmon@iuvax.cs.indiana.edu (RAMontante) (08/16/89)

wek@point.UUCP (Bill Kuykendall) <[1524.4]comp.ibmpc;1@point.UUCP> :
-It seems to me that this must vary with the version of 'DOS.  Compaq DOS
-3.31 most definitely reinitializes the FAT when fdisk is run.  On the other
-hand, I'm certain that I've recovered hard disks that had been fdisk'ed in
-the past.  

Good point, although it isn't the DOS version per se.  My Zenith v3.21
release, for example, doesn't supply `fdisk'; instead it supplies
`part', and the documentation says "Any changes you make to the
partition table with PART can destroy all existing data on your hard
disk."  On the other hand, a partitioning program that I played with as
part of Minix certainly did not remove data; at one point I was
repartitioning the disk repeatedly while trying to install Minix, and
the files in the DOS partition stayed put even if I accidentally frobbed
that partition as well as the others.

harvey@nems.arpa (Harvey) (08/18/89)

In article <24673@iuvax.cs.indiana.edu> bobmon@iuvax.cs.indiana.edu (RAMontante) writes:
>Good point, although it isn't the DOS version per se.  My Zenith v3.21
>release, for example, doesn't supply `fdisk'; instead it supplies
>`part', and the documentation says "Any changes you make to the
>partition table with PART can destroy all existing data on your hard
>disk."  On the other hand, a partitioning program that I played with as

Although the Zenith documentation warns that changing the partition table
will destroy all data, it actually doesn't.  I have changed many partition
tables on Zenith Dos, v 3.11, 3.21 and 3.3 and have yet to lose any data.

Betty Harvey
David Taylor Research Center
harvey@nems.arpa