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Posted: 2004-04-04 03:17am
by Pu-239
Warning from the shred manpage (utility to overwrite files under Linux/Unix):
CAUTION: Note that shred relies on a very important assumption: that
the filesystem overwrites data in place. This is the traditional way
to do things, but many modern filesystem designs do not satisfy this
assumption. The following are examples of filesystems on which shred
is not effective:
* log-structured or journaled filesystems, such as those supplied with
AIX and Solaris (and JFS, ReiserFS, XFS, Ext3, etc.)
* filesystems that write redundant data and carry on even if some
writes
fail, such as RAID-based filesystems
* filesystems that make snapshots, such as Network Appliance's NFS
server
* filesystems that cache in temporary locations, such as NFS
version 3 clients
* compressed filesystems
In addition, file system backups and remote mirrors may contain copies
of the file that cannot be removed, and that will allow a shredded file
to be recovered later.
Of course, if you are disposing of a hard drive, you can just shred the entire device file like the man page says, or dd pseudorandom values from /dev/urandom to /dev/hda or whatever, and then dump zeros for a couple of times, which would get rid of the journaling problems.
By the way, why are you disposing the drive? Why not put it into a computer for use as a second hard drive (unless it's broken of course, then you can't overwrite it and will have to destroy it physically).
Posted: 2004-04-04 10:15am
by Darksider
Why am I disposing of them?
The computers are at least 5-6 years old
The hard drive that's already been smashed into little peices anyway. The other one is even older.
(It doesn't even have windows.)
Posted: 2004-04-04 12:28pm
by Rye
Icehawk wrote:I have always wondered about this magical "recovering" or "undeleting" of files. How the hell does it work? how the hell is it even possible especially if you've taken a magnet to the drive or smashed it up?
Please forgive my ignorance.
Essentially, when you delete something, you're telling the computer it's allowed to write on that section of hard disk again, it doesn't actually remove the information. You can get stuff which rewrites over that stuff multiple times though, to make it really difficult to retrieve. Which is essentially what the magnet does, since harddrives do all their stuff by magnetic marks on the cd-like magnetic discs inside.
Posted: 2004-04-04 12:36pm
by Anarchist Bunny
T
H
E
R
M
I
T
E
It utterly destroyes the thing, and you get to play with thermite!
Posted: 2004-04-04 01:14pm
by Enigma
You can do what the Pentagon does. From what I understand is that they wipe the drive clean and crush the HD into a fine powder and store it.
Posted: 2004-04-04 01:56pm
by Pu-239
Darksider wrote:Why am I disposing of them?
The computers are at least 5-6 years old
The hard drive that's already been smashed into little peices anyway. The other one is even older.
(It doesn't even have windows.)
Um... my Desktop is 5-6 years old. 5-6 years old is usable. Hell anything newer than 1995 is usable.
Posted: 2004-04-04 02:14pm
by Darksider
Pu-239 wrote:Darksider wrote:Why am I disposing of them?
The computers are at least 5-6 years old
The hard drive that's already been smashed into little peices anyway. The other one is even older.
(It doesn't even have windows.)
Um... my Desktop is 5-6 years old. 5-6 years old is usable. Hell anything newer than 1995 is usable.
We got the newer one in 1993, and the older one in 1990
Posted: 2004-04-04 08:47pm
by Uraniun235
Oh, just write zeros to the whole hard drive and then break it to pieces, nothing short of spending thousands and thousands of dollars would be able to retrieve any usable data from it, and there are way too many hard drives that are tossed away intact for con artists to waste their time and money with platter fragments.
Posted: 2004-04-04 09:13pm
by Crayz9000
Well, if you have broadband and don't have a firewall or router, you can go to
http://www.freesco.info and get Freesco. It'll run off a floppy disk, and all you need is a 386 with 16 megs of RAM and a couple of network cards.
You can also use it as a small webserver, or a print server (like if you want to be able to print to a printer from any computer in the house, and not have to worry about running downstairs to turn Mom's computer on or whatever so you can print).
Posted: 2004-04-04 10:06pm
by aerius
You will need a car battery, a set of jumper wires for jumpstarting cars, and a small metal rod. Take the drive apart and see if you can separate the individual platters. Hook up the jumper cables to the battery, clamp one of them to the platter, clamp the metal rod to the other, and drag the rod across both sides of the platter a few times. This is the poor man's arc welder, just don't zap yourself. It'll vapourize any part of the disc it touches, and the sparks and smoke are pretty cool. Fun stuff.