Comments on: What’s The Best Way To Erase A Hard Drive? http://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/ Helping Normal People Get Their Geek On Wed, 15 Feb 2012 10:29:00 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Robhttp://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/comment-page-1/#comment-34187 Rob Mon, 26 Oct 2009 12:04:44 +0000 http://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/#comment-34187 Obviously, I mean if you are selling a used pc that you are going to keep , say, the same windows operating system on Obviously, I mean if you are selling a used pc that you are going to keep , say, the same windows operating system on

]]> By: Robhttp://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/comment-page-1/#comment-34183 Rob Mon, 26 Oct 2009 11:59:53 +0000 http://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/#comment-34183 I'd just thought I'd like to add, that it is essential to run a basic eraser program to get rid of cookies and cashe and passwords and stuff, and also to delete the pagefile.sys file before you erase the slack space on any hard drive. I’d just thought I’d like to add, that it is essential to run a basic eraser program to get rid of cookies and cashe and passwords and stuff, and also to delete the pagefile.sys file before you erase the slack space on any hard drive.

]]> By: Drive Guyhttp://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/comment-page-1/#comment-32116 Drive Guy Tue, 15 Sep 2009 01:26:33 +0000 http://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/#comment-32116 Rich, I agree with you about the format command. A "format c:" only clears out a few areas in the file system and the links, or pointers, to those locations on disk. Files are easily recoverable. However I disagree with you about a single pass wipe on a drive. A single pass of 1's or 0's or whatever else you like is more then enough to stop someone from reading your drive. The days of reading "off-track" data have been long gone. Though it's true there could be data in those regions, it would take millions of dollars of equipment to not only scan those regions of the drive, but to also decipher the encoding scheme used to write that data to the spinning platters, not to mention taking out the drive positioning information(servo) that is written every few sectors, sometimes right in the middle of them. No software has the smarts to get the heads to read off track and decipher this information. If people are looking at your drives that close, you better leave the country! Rich, I agree with you about the format command. A “format c:” only clears out a few areas in the file system and the links, or pointers, to those locations on disk. Files are easily recoverable. However I disagree with you about a single pass wipe on a drive. A single pass of 1′s or 0′s or whatever else you like is more then enough to stop someone from reading your drive. The days of reading “off-track” data have been long gone. Though it’s true there could be data in those regions, it would take millions of dollars of equipment to not only scan those regions of the drive, but to also decipher the encoding scheme used to write that data to the spinning platters, not to mention taking out the drive positioning information(servo) that is written every few sectors, sometimes right in the middle of them. No software has the smarts to get the heads to read off track and decipher this information. If people are looking at your drives that close, you better leave the country!

]]> By: Saveriohttp://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/comment-page-1/#comment-31017 Saverio Tue, 25 Aug 2009 04:45:11 +0000 http://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/#comment-31017 ...Which raises the question: How do you perform a valid DoD-7 formatting on Linux? By the way, thanks for the 'urandom' tip. ;-) …Which raises the question: How do you perform a valid DoD-7 formatting on Linux?
By the way, thanks for the ‘urandom’ tip. ;-)

]]> By: Rich Mengahttp://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/comment-page-1/#comment-31014 Rich Menga Tue, 25 Aug 2009 02:27:57 +0000 http://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/#comment-31014 The UNIX dataset definition command's primary purpose is for low-level copying and conversion of raw data, and not as a magnetic drive formatting utility. If you "dd" a drive, it is no more secure in erasure than FORMAT C:.[edit]One more note: If you were to use dd in a semi-secure way to wipe a drive, the proper way would be this:dd if=/dev/urandom of=/dev/hdaThat will wipe an entire disk with random data. But it's still nowhere near as good as DoD-7. The UNIX dataset definition command’s primary purpose is for low-level copying and conversion of raw data, and not as a magnetic drive formatting utility. If you “dd” a drive, it is no more secure in erasure than FORMAT C:.

[edit]

One more note: If you were to use dd in a semi-secure way to wipe a drive, the proper way would be this:

dd if=/dev/urandom of=/dev/hda

That will wipe an entire disk with random data. But it’s still nowhere near as good as DoD-7.

]]> By: Saveriohttp://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/comment-page-1/#comment-31012 Saverio Tue, 25 Aug 2009 02:19:16 +0000 http://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/#comment-31012 Does that mean that (on Linux) the operation "dd if=/dev/zero of=/dev/hda" should be repeated at least 7 times? :-o Does that mean that (on Linux) the operation “dd if=/dev/zero of=/dev/hda” should be repeated at least 7 times? :-o

]]> By: Rich Mengahttp://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/comment-page-1/#comment-31009 Rich Menga Tue, 25 Aug 2009 01:21:13 +0000 http://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/#comment-31009 No. A 1-pass (which is what you're referring to) is no more secure than FORMAT C:. The DoD-7 formats, verifies and uses random characters to ensure secure erasure. 1-pass method can have data recovered easily. DoD-7 is a whole lot more difficult to do the same.The most secure that exists is the Gutmann 35-pass. This takes an excruciatingly long time to complete, but for the most secure erasure of super-sensitive data, there is no better. No. A 1-pass (which is what you’re referring to) is no more secure than FORMAT C:. The DoD-7 formats, verifies and uses random characters to ensure secure erasure. 1-pass method can have data recovered easily. DoD-7 is a whole lot more difficult to do the same.

The most secure that exists is the Gutmann 35-pass. This takes an excruciatingly long time to complete, but for the most secure erasure of super-sensitive data, there is no better.

]]> By: David Mhttp://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/comment-page-1/#comment-31005 David M Tue, 25 Aug 2009 01:06:16 +0000 http://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/#comment-31005 I'm curious, wouldn't it be just as secure for the disk to be written to all zeros the first time rather than erasing it seven times over? I’m curious, wouldn’t it be just as secure for the disk to be written to all zeros the first time rather than erasing it seven times over?

]]> By: Saveriohttp://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/comment-page-1/#comment-30985 Saverio Mon, 24 Aug 2009 17:01:02 +0000 http://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/#comment-30985 I almost forgot... Use that command with extreme caution. Make sure the volume is the right one. ;-) I almost forgot… Use that command with extreme caution. Make sure the volume is the right one. ;-)

]]> By: Saveriohttp://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/comment-page-1/#comment-30984 Saverio Mon, 24 Aug 2009 16:58:50 +0000 http://www.pcmech.com/article/whats-the-best-way-to-erase-a-hard-drive/#comment-30984 For those of you who use Linux like myself, there is a very easy method. Open a terminal and then type:dd if=/dev/zero of=/dev/hda (*)* Or replace 'hda' with whatever volume your interested in formatting For those of you who use Linux like myself, there is a very easy method. Open a terminal and then type:

dd if=/dev/zero of=/dev/hda (*)

* Or replace ‘hda’ with whatever volume your interested in formatting

]]>