SUMMARY: purging a disk

From: Wyllys Ingersoll (
Date: Fri Feb 05 1993 - 16:20:40 CST

thanks to all who responded, here is my original post:

> Is it possible to purge a whole disk from within a program?
> For example: the program is running in Motif and the user must quickly
> erase the disk for security reasons, a 'kill disk' button is provided
> for this purpose.
> I don't believe it is possible to do this without going into the miniroot
> or running from a RAM disk partition and then running format, but I need
> to verify this fact.

Well, many people responded, some couldn't beleive I would ever want
to do such a thing. Believe it.

As some people guessed, the purge must be a 'real' purge and it must
be DoD approved, which eliminates the most common suggestions, anyway
here are the suggestions I got.

1. Do a newfs on the partition to be purged
   - this only makes the disk appear to be wiped, the data is still there.
     No good.

2. Do 'dd if=/dev/zero of=/dev/RAWDEVICE'.
   - While this may work, it is not DoD approved and will not be because it
     cannot write complementary patterns of 1's and 0's to the disk in
     3 passes.

3. Hit the 'off' button, just as effective.
   - WRONG.

4. Use Plastic explosives.
   - Not "user friendly".

5. Get a product called 'Scrub' or 'Shred' from Los Altos Technologies
   - Claims to be DoD approved, but I have not verified this.

6. Run format
   - Cannot be run on mounted partitions.

Well, I haven't decided what, if anything, I can do about this requirement.
It seems that the Scrub program may be the way to go. I need to
clean the WHOLE disk, /, /usr, and everything else, mounted or otherwise.
Some people didn't understand that part.

Thanks to all who responded:!tommy!hightowr!jaf!CAMPANI!Daniel

 Wyllys Ingersoll E-Systems, Melpar Div. Ashburn, VA

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