topic Re: Erase Hard Drives in Operating System - Linux

Erase Hard Drives

Ragni Singh — Thu, 22 Jan 2009 20:41:32 GMT

Hello, what's the best way to erase data of a hard drive. It currently has Linux OS installed.

Make the system unbootable.

Thanks and points will be assigned.

Re: Erase Hard Drives

Shoghi Martinez G. — Thu, 22 Jan 2009 22:13:08 GMT

Use a linux live CD boots an get a terminal window and use the dd command : dd if=/dev/zero of=/dev/hdx bs=1k

hdx is the hard drive device file, change it.

Re: Erase Hard Drives

Ragni Singh — Thu, 22 Jan 2009 23:00:24 GMT

Actually, that doesn't work. I run parted.....rm..then minor number.

Re: Erase Hard Drives

Jared Middleton — Thu, 22 Jan 2009 23:33:37 GMT

Some interesting reads...

http://www.engadget.com/2005/03/15/how-to-erase-old-hard-disks/

http://linuxhelp.blogspot.com/2006/06/how-to-securely-erase-hard-disk-before.html
(may wish to also review the comments)

http://www.geocities.com/thestarman3/asm/mbr/WIPE.html#HOW

Re: Erase Hard Drives

Ben Stokes — Fri, 23 Jan 2009 09:43:25 GMT

I use DBAN : http://sourceforge.net/projects/dban/

Very flexbile and offers quite a few options depending on your security requirements - if your data was particularly sensitive you can use the most paranoid option which writes random patterns of ones and zeros over the disks several times over.

Re: Erase Hard Drives

Ivan Ferreira — Fri, 23 Jan 2009 12:36:45 GMT

The 'shred' command normally is used for this purpose.

Re: Erase Hard Drives

Don Vanco - Linux Ninja — Fri, 23 Jan 2009 15:49:48 GMT

DBAN - meets a number of cert requirements, including (I believe) one from the DOD. We've hooked a server up to a SAN and blasted it in its entirety.

Re: Erase Hard Drives

Hemmetter — Mon, 26 Jan 2009 08:12:20 GMT

Hello,

for me the method with "dd" is the best because it is straight 'n easy.

And it is good enough for securely delete any diskdata.

See that interesting article on heise online:
http://www.heise-online.co.uk/news/Secure-deletion-a-single-overwrite-will-do-it--/112432

rgds
HGH

Re: Erase Hard Drives

Fredrik.eriksson — Mon, 26 Jan 2009 10:07:42 GMT

Well, as dennis said, shred is usually used... this is because writing the entire disk with 0's won't make it "unrestorable".. shred overwrites with useless and random data, and I believe the default amount of times written is 25. This is not 100% secure either, but it makes it alot more expensive to restore the drive :P

You could imitate this by using dd with if=/dev/urandom but this will take very long and use alot of cpu.

Another alternative if you just want it to be unbootable but you want to reuse the disk, then I would just recommend booting on a live cd (or rescue) and run a partition editor like cfdisk and remove the partitions... This won't clear the MBR thou so if you have a LILO or GRUB in your MBR that will remain...

According to this forum post: https://www.linuxquestions.org/questions/linux-general-1/wiping-mbr-197530/
This would work to clean the mbr also (hda being the drive you have your MBR on):
dd if=/dev/zero of=/dev/hda bs=512 count=1

Best regards
Fredrik Eriksson

Re: Erase Hard Drives

Maaz — Mon, 26 Jan 2009 12:51:31 GMT

I also agree with those who recommend 'dd'

as I have used 'dd' to erase disk and use 'foremost' to recover the data, and failed

and same goes with shred.

i.e 'dd' and 'shred' both erases the disk, so that most of the data recovery software doesn't able to recover

Regards