Erasing hard disk contents using dd or dcfldd

jake24 · #1 (**permalink**) 06-02-2009

Hi,

I am writing a script to wipe my hard disk, in a relatively secure manner by over-writing the disk with 3 patterns. So, I run the dd/dcfldd command 3 times with a sync call in between each command call in the script.

Code:

#!/bin/sh
dcfldd pattern=99 conv=notrunc of=/dev/sda
sync
dcfldd pattern=jj conv=notrunc of=/dev/sda
sync
dcfldd pattern=hell conv=notrunc of=/dev/sda
sync

I want to know if the above code would in fact,result in my hard disk being over-written with the given patterns in that order? Since I have introduced a sync in between each command call, any remaining buffers to be written onto the disk would have been physically written before the next pattern is being copied to the disk by dcfldd.

Please help me. I really want to understand the impact.

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
minfree contents of the disk	vr_mari	SUN Solaris	7	05-15-2009 03:01 PM
hard disk and san	lo-lp-kl	AIX	4	06-12-2008 02:13 PM
Hard Disk	hmaraver	UNIX Desktop for Dummies Questions & Answers	4	07-03-2005 04:50 PM
RAM, Hard Disk	ramaraju	UNIX for Dummies Questions & Answers	2	03-01-2005 08:35 PM
How to Copy Contents from CD to Hard disk	vr76413	UNIX for Dummies Questions & Answers	4	07-06-2003 01:20 AM

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Switch to Linear Mode Switch to Hybrid Mode Threaded Mode	Rate This Thread:


	Powered by