Zeroing an Apple Macintosh Hard Drive
To ensure that all
confidential data has been removed from a computer system and cannot be
restored using data restoration tools, as well as to ensure that the
computer is in compliance with all software licensing issues, all
information on the hard drive should not only be deleted but also
overwritten (also known as zeroing out the drive). This applies not
only to computers going to off-campus locations, but also to ones going
to another individual at Lehigh as that individual is unlikely to have
the same access rights to confidential information as the original user
of the system. Instructions for doing so on an Apple Macintosh follow.
For Mac OS X 10.2.3 or later:
This process should work for any hard drive shipped from Apple as part
of a Mac OS X-compatible computer. It may not work on third party hard
drives (i.e., those not shipped by Apple).
- Restart the computer from a system CD (i.e., press and hold the C
key during the startup sound to start up from CD).
- Do not click on Continue from the Installer screen; instead,
choose Installer > Open Disk Utility (or, depending on
the version,
start DiskUtility [found in
/Applications/Utilities]).
- In the drives window, highlight the hard drive (e.g.,
"72GB ST24554" not "Macintosh HD") you intend to
erase, and click on Options.
- Select 8 Way Random Write Format
and
click
on Erase.
Note: This process is designed to produce a high level of security for the erased drive and may take a number of days to complete.
For Mac OS 9 or earlier:
For machines using MacOS 9 or earlier use either Drive Setup, Apple HD
SC
Setup, or Internal HD Format. Select the option to zero out (if
present) or the option to low level
format the disk. These programs are typically on the Mac OS install CD
within the Utilties Folder. See Apple Tech
Note
21103 for additional information.
For additional assistance in zeroing a hard drive, contact your
Computing Consultant.