Question about zeroing data on hard disk

[quovadis]

I have noticed this a couple of times when doing a fresh reinstall of Leopard:

If I use the option to "zero data once" with disk utility from installation disk and then do a fresh install of leopard, all the information is not removed from my internal hard disk.

In particular, the spotlight privacy settings are retained. For example, when I attach my backup hard disk after the fresh install, I discover that it automatically appears under the "privacy" tab in the spotlight settings. The same happens for my Eyetv folder.

Is there a way to ensure EVERYTHING really is erased before a fresh install of the OS?

 

[darwinian]

I have noticed this a couple of times when doing a fresh reinstall of Leopard:

If I use the option to "zero data once" with disk utility from installation disk and then do a fresh install of leopard, all the information is not removed from my internal hard disk.

In particular, the spotlight privacy settings are retained. For example, when I attach my backup hard disk after the fresh install, I discover that it automatically appears under the "privacy" tab in the spotlight settings. The same happens for my Eyetv folder.

Is there a way to ensure EVERYTHING really is erased before a fresh install of the OS?

Are you using Migration assistant or moving your home folder contents over after the install?

 

[Amdahl]

Those are probably defaults, not retained information.

If your backup hard disk is a Time Machine disk, I'm pretty sure it doesn't get indexed.

 

[quovadis]

Are you using Migration assistant or moving your home folder contents over after the install?

Your question is very insightful - hadn't thought about this. Here is what I do:

I don't use migration assistant. I have a folder in the "Documents" folder, say folder named "X"
Before an OS re-install, I copy this folder to an external and after the re-install I copy from the external to the internal hard disk (to the "Documents" folder)

thanks

 

[Consultant]

How long did it took to zero data? Few hours or minutes? Perhaps you didn't actually zero out the disk.

 

[quovadis]

How long did it took to zero data? Few hours or minutes? Perhaps you didn't actually zero out the disk.

It took a long time. I don't recall the exact figure but I want to say something like close to an hour

 

[darwinian]

Someone who knows should confirm this, but that sounds funny -- almost like those folder specific settings are in .DS_Store, which I wouldn't have thought.