On Fri, 20 Jan 2012, Yaron wrote:

> On Fri, 20 Jan 2012, wes smith wrote:
>
>> One does not simply throw a harddrive into Mordor.
>
> I need to put that on a t-shirt. Or maybe a twinkie.

Hostess may go out of business, so hurry to buy that Twinkie, but once you 
have one, you have time because they have a shelf life of 100,000 years.

But seriously -- regarding /dev/zero -- does anyone think there are any 
*real* worries about data recovery after you've filled the drive with 
zeros?  I know if I was working on a secret project at Microsoft, I 
wouldn't fill my old drive with zeros and then hand it to developers at 
Apple or Oracle, but if we're talking about giving a personal hard drive 
to someone who just wants to use it in their personal computer, isn't use 
of /dev/zero plenty?

Jeremy pointed out that /dev/urandom would use random bits.  I would think 
that /dev/urandom would be a better choice than /dev/zero.  Is there any 
reason to prefer /dev/zero?  In other words, isn't this a really good 
answer:

dd if=/dev/urandom of=/dev/<drive>

Is it really even necessary to do that twice?

Related question:  Every drive on my system seems to get three entries in 
/dev like so:

/dev/sdb
/dev/sdb1
/dev/sdb2

To properly mess up that drive, can I just do this?:

dd if=/dev/urandom of=/dev/sdb

Or do I have to do this?:

dd if=/dev/urandom of=/dev/sdb1

Because sdb1 seems to be the mounted partition with the data.

Mike