Erase harddrive!

[Matsaki]

Hi,
I am working for a Company that some times get in old Macs. Before we can resell them, we need to erase the harddrive properly. What application would suit us for that?

I have heard that a harddisk must be erased 8 times to be completely emty?

 

[CaptainQuark]

Why not just use Disk Utility? You can erase the disk, using the "Zero All Data" function. Run that a few times and nothing will be recoverable.

 

[Randman]

If you really want to be complete, select the turbo erase. It'll take longer but you'll only need to do it once.

 

[scruffy]

Disk Utility offers a couple of erase modes - you can just zero the disk, or you can do the full seven or eight pass (I forget which) erase.

 

[Viro]

This is something that I've always been meaning to ask. What is the 8 pass erase? How could anything be better than completely zeroing all data?

 

[mdnky]

In simplest terms, it goes through and mangles the data 8 different times.

 

[brianleahy]

How could anything be better than completely zeroing all data?

I guess that, in theory, someone incredibly determined could open the drive (under clean-room conditions) remove the platters and then use certain highly-sensitive equipment to detect ones that were recently overwritten a single time.

As far as I know though, there are no commands you can send to a still-sealed drive and recover data from sectors that were overwritten.

 

[scruffy]

A single pass will probably be good against file recovery programs. The multiple passes are against people with a scanning electron microscope and a lot of time on their hands.