Hosted by site sponsor WebMate.
PowerBook G4 Q&A - Updated December 6, 2006
To be notified of new Q&As, sign up for EveryMac.com's bimonthly email list.
How can I securely erase the entire hard drive on my PowerBook G4 before selling it?
You are wise to want to completely erase the data on your PowerBook G4 before selling it. Files just "thrown away" can be retrieved easily.
There are a variety of methods that can be used to erase the hard drive in your system so that it would be extremely challenging, even close to "impossible", for a third-party to retrieve data.
If you have a MacOS X 10.4 "Tiger" DVD, start your PowerBook from the DVD, and select "Disk Utility" from the "Installer" menu.
From within Disk Utility, select the drive to erase, click on the "Erase" tab, and then click the "Security Options..." button. The two secure options are "7-Pass Erase" and "35-Pass Erase", which overwrite and erase the entire drive seven times and thirty five times, respectively. Generally, the 7-Pass Erase option is expected to take a few hours, and the 35-Pass Erase is expected to take 24 hours. However, at least one MacWorld Forums user lamented that the 7-Pass Erase option took "nearly two days" on his iBook and there was "no notice that [the] computer would be inaccessible for this amount of time". One should be mindful that it may take a very long time. Certainly you will need to have your PowerBook G4 plugged in during the entire process.
If you have a MacOS X 10.3 "Panther" CD-ROM, you can erase the drive in a manner that is generally considered to be roughly equivalent in security to the to "7-Pass Erase" option in MacOS X 10.4 "Tiger". Start your PowerBook from the CD and select "Disk Utility" from the "Installer" menu. Using Disk Utility, select the appropriate drive, click the "Erase" tab, click the "Options" button and use the "8 Way Random Write Format" method. Like the secure methods in MacOS X 10.4 "Tiger", this will take many hours.
If you only have the MacOS X 10.2.7 CD that was shipped with your PowerBook G4, it would be advisable to consider a third-party solution to securely erase the data on your drive. Corporate users who need to erase data to conform to a particular security standard in accordance with policy might also find a third-party utility to be helpful.
Although other programs also may be available, a popular one is SuperScrubber. There are separate versions for systems with G3, G4, and G5 processors for US$29.99 each, or a "value pack" that includes all three versions for US$49.99.
The SuperScrubber FAQ defines the program as:
A disk utility that serves to completely and permanently erase all data from a specified internal or external hard drive or partition, leaving no retrievable trace of the old data. Using SuperScrubber allows you to give away or sell your old computer without any worries, knowing that it no longer contains personal or confidential data.
The website also notes that it erases the drive in accordance with "U.S. Department of Defense 5220.22 M" standards. Wikipedia defines this particular DoD standard as "overwriting data in 3 passes -- with a character, then its complement, and finally with a random character; e.g., overwrite first with 0000 0000, followed by 1111 1111, then 1001 0111."
The screenshots show that other standards are available as well, and the program also provides a helpful estimate of the time remaining.
By properly using any of these methods you should be able to sell your system knowing that for all practical purposes your data never will be retrieved by a third-party.
If you are interested in more about securely erasing the data from a computer, you might also find the highly respected Peter Guttmann's academic "Secure Deletion of Data from Magnetic and Solid-State Memory" to be a worthwhile read.
Permalink | Report an Error/Typo | Sign Up for Site Update Notices
Established in 1996, EveryMac.com has been created by experts with decades of experience with Apple hardware. EveryMac.com includes, and always has included, original research incorporating detailed, hands-on inspection of packaging, computers, and devices as well as extensive real-world use. All information is provided in good faith, but no website or person is perfect. Accordingly, EveryMac.com is provided "as is" without warranty of any kind whatsoever. EveryMac.com, and the authors thereof, shall not be held responsible or liable, under any circumstances, for any damages resulting from the use or inability to use the information within. For complete disclaimer and copyright information please read and understand the Terms of Use and the Privacy Policy before using EveryMac.com. Copying, scraping, or use of any content without expressed permission is not allowed, although links to any page are welcomed and appreciated.