>Date: Tue, 29 Jul 1997 15:04:41 -0400
>From: "Louis T. Chmielewski" <chmielewskil @
sprynet .
com>
>Subject: More info on 'deleted' files...
>
>Greetings all,
> I'd like to find out more info about 'deleted' files on our pcs and vaxs.
>For instance, how is a 'deleted' file ultimately deleted? What process is
>involved to truly delete a file from magnetic media? We might be looking
Depending on who you listen to but heres the short version.
If vms is setup with highwatermark (clear on allocate/ deallocate)
the space on the disk is overwritten on both allocate and deallocate ie
when deleted and when reused.
Dos dos nothing to delete a file. It simply changes the file allocation table
to show the area available, thus the undelete command in dos.
The safest way is to destroy all media when done with it. Barring that an
overwrite process the overwrites using the "dod" method is pretty good.
Ask your self/management will it be worth someones time to use a electron
microscope on the original media or can we assume only software recovery will
be used. ie nortons disk edit. Normal software can not recover from an overwrite
but multiple overwrites is not enough to cover data if the drive is subjected
to electron microscopes etc....
>to purchase some s/w product that could 'scrub' our drives, getting rid of
>'deleted' files, but I'd like to learn more about the process first.
Done this been there what kind of drives and whats your motive/incentive?
> Thanks,
> Lou
>Louis T. Chmielewski
>Security Manager/DBA
>Doctor's Associates Inc. (Subway)
>(203) 877-4281 x1128
I hope this helps.
Donald J Smith Network Security Engineer @CDInt
get a clue; buy one if you must but just get one.
(my opinions are mine and so are the spelling errors ;-)
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