Macintosh OS/Zero All Data


Hi David,

I use a PowerPC G4 Dual 1 GHz (QuickSilver 2002); 1.5 GB SDRAM; and run Mac OS X 10.4.11 Tiger.  Is it possible to "zero all data" on ATA and SATA internal hard drives and on external "Mac Companion?"


It is an option in Disk Utility in Erase click Options

Zeroing all data takes longer than a normal disk initialization, up to several hours for a large hard drive, so you should plan accordingly.

Availability of zero all data feature

   For Mac OS X, zeroing is available in version 10.2.3 or later.
   The zero all data option should work with any hard drive originally shipped from Apple as part of a Mac OS X-compatible computer.
   Zero all data only works for whole disks. If you have partitioned, you cannot zero an individual partition.
   This option may or may not work with third-party hard drives.

Steps for zeroing data

These steps assume you have a Mac OS X 10.2.3 or later CD:
   1. Insert the Mac OS X CD.
   2. Restart the computer.
   3. Immediately after the startup sound, press and hold the "C" key to start up from CD.
   4. When the Installer screen appears, do not click Continue. Instead, choose Installer > Open Disk Utilities.
   5. Select the hard drive to erase.
   6. Click the Erase tab.
   7. Select the volume format from the Volume Format pop-up menu.
   8. Click Options.
   9. Select the checkbox for "Zero all data".
   10. Click OK.
   11. Click Erase.  

Macintosh OS

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David Anders


Seattle - The Computer Guy - 15 yr veteran Mac/PC/network problem solving. Clients are design firms, artists, freelancers and photographers. PLEASE PLEASE provide EXACT info for Mac Model and OS Version. RAM installed - added cards - external devices - recent changes. Do you do MONTHLY MAINTENANCE? With what Utility? What you have tried and what result do you want.


First computer experience 1969. Worked in 3 computer stores. Setup First Mac and First IBM-PC.

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