Who will be the last HD maker down the road?

[vintagecoder at aol.com]

On Wed, 09 Mar 2011 15:30:30 -0600
cctalk-request at classiccmp.org wrote:

> Message: 22
> Date: Wed, 09 Mar 2011 12:46:24 -0800
> From: Eric Smith <eric at brouhaha.com>
> Subject: Re: Who will be the last HD maker down the road?
> To: General Discussion: On-Topic and Off-Topic Posts
> 	<cctalk at classiccmp.org>
> Message-ID: <4D77E720.3050100 at brouhaha.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> 
> Richard wrote:
> >  Flash memory is problematic for secure data.  Basically, its nearly
> >  impossible to securely erase a file from flash based disks.  
> 
> vintagecoder at aol.com wrote:
>  > I don't know how that can be true. I can understand deleting doesn't
>  > work but is it true a simple dd if=/dev/zero of=/dev/sdx onto the
>  > flash card doesn't fill it with zeros?  
> 
> That's *exactly* the problem.  It doesn't.  dd only fills the blocks 
> that are currently in use, but the card may have spared out marginal 
> blocks that still contain residual user data.

Then I would think a few passes of filling it with random data should work.

> This is true of modern hard drives as well.

I like flash because you can snap them in pieces easily ;) All the theory
comes to an end at my pair of vice grips!

> 
> That's why the "secure erase" commands were added to the ATA command 
> set, and the drive is supposed to erase even the spared blocks.

I don't trust that to work. But I do trust my vice grips.