Go Back   The macosxhints Forums > OS X Help Requests > System



Reply
 
Thread Tools Rate Thread Display Modes
Old 03-28-2012, 01:49 PM   #1
drman7
Triple-A Player
 
Join Date: Mar 2009
Posts: 74
Clear my Mac

Could someone tell me how to totally wipe out my HD so there is no possible way it can be restored. I'm giving my 13" Mac Pro (about 2 yrs old) to my eldest daughter and our living trust and other legal docs are on this Mac which could cause a family rift if she saw it... I know on program like CIS they can always extract things from the hard drive no matter what but I've been told thats not true, it is possible to wipe out the HD. Can someone help me out with this... Thank you in advance
drman7 is offline   Reply With Quote
Old 03-28-2012, 02:24 PM   #2
fracai
MVP
 
Join Date: May 2004
Posts: 2,087
CSI is television.

While it may technically be possible to recover data that has been overwritten, in practice it's very difficult and usually impossible.

So, what you want to do depends on how you're giving away the machine.

If you're going to reinstall the OS you can overwrite the drive with zeros before installing. Boot from your install media and use DiskUtility to zero out the drive before installing.

If you're just deleting sensitive files and then giving her the machine, you want to use DiskUtility to "Erase Free Space": http://support.apple.com/kb/HT3680

In the future, keep your sensitive documents in an encrypted disk image. Then you don't have to worry about them being recovered after deleting the image, even if CSI gets a hold of it ;-)
fracai is offline   Reply With Quote
Old 03-28-2012, 02:25 PM   #3
DeltaMac
League Commissioner
 
Join Date: Jan 2002
Posts: 8,500
Pretty simple, really...
Boot to your original restore OS X DVD (which should be transferred with the MacBook Pro, anyway)
Run Disk Utility from the Utilities menu.
Click on your drive, then click the Erase tab.
Click on Security Options, and choose Zero out data, and click OK, then click the Erase button.
There's little need to go to higher levels for a multi-pass erase, plus the drive is treated pretty hard during the process.
Anyway, that process will write data to all blocks, and make the old data essentially unrecoverable. If you continue with reinstalling OS X after the erase, then that makes any possibility of discovering any old data only available to true experts - and really unlikely for anyone other than the truly paranoid.
DeltaMac is offline   Reply With Quote
Old 03-28-2012, 03:47 PM   #4
drman7
Triple-A Player
 
Join Date: Mar 2009
Posts: 74
Thank you for the great advice and info... This site is awesome, maybe one day I'll be knowledgeable enough to help others but at 65 I seriously doubt it, this is a young persons gig... Thanks again
drman7 is offline   Reply With Quote
Old 03-28-2012, 06:21 PM   #5
acme.mail.order
League Commissioner
 
Join Date: Sep 2003
Location: Tokyo
Posts: 6,328
For people who keep national secrets on their drive, know the grand unification theory, the location of Christ's bones, the plans for iPhone 6, or the truly, truly paranoid, it's very simple:

Go buy a new drive. Install a new copy of the OS and any files you want. Then pop the cover off the old drive and yank out the platters*. Use a big screwdriver, a hammer, and some brute force. If it's glass, it will shatter**. If it's metal, heat it with a torch until it's bright red. If it's an SSD, just melt the chips.

Total cost: about $150.
Total time: Couple of hours. Much faster than a "secure erase"

* some drives have more than one
* goggles, gloves, don't do it in the kitchen etc.
acme.mail.order is online now   Reply With Quote
Old 03-28-2012, 08:03 PM   #6
DeltaMac
League Commissioner
 
Join Date: Jan 2002
Posts: 8,500
2 or 3 holes drilled completely through the drive will also be much faster than a long 'wipe'
DeltaMac is offline   Reply With Quote
Old 03-29-2012, 02:05 PM   #7
drman7
Triple-A Player
 
Join Date: Mar 2009
Posts: 74
Thanks I'll keep the new HD thing in mind but for now I feel the erase thing will work... Thanks to all
drman7 is offline   Reply With Quote
Old 04-09-2012, 11:19 AM   #8
Nuclear.Glow
Prospect
 
Join Date: Apr 2012
Posts: 5
There is a simple equation you need to know: cost of recovery/reward (keeping in mind that there are simpler ways to your data ). Deep recovery is possible, but costs quite a bit in equipment. The easiest way to prevent recovery is avoiding data to be there in the first place, so a new hard disk is the best.

For your future computer use I'd recommend you install Truecrypt and learn to work with it - it creates secure archives which you can mount like external drives or USB sticks, and the data is portable to Windows as well.
Nuclear.Glow is offline   Reply With Quote
Old 04-09-2012, 11:21 AM   #9
Nuclear.Glow
Prospect
 
Join Date: Apr 2012
Posts: 5
I think the query about secure erase had more to do with a desire to retain the OS; but I think a new drive is a good idea anyway - I wouldn't trust a drive that's more than 3 years old anyway..
Nuclear.Glow is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT -5. The time now is 09:28 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Site design © IDG Consumer & SMB; individuals retain copyright of their postings
but consent to the possible use of their material in other areas of IDG Consumer & SMB.