[PATCH] mkswap: generate UUID

[Rob Landley]

On Thursday 18 June 2009 17:53:35 Colin Watson wrote:
> On Thu, Jun 18, 2009 at 05:24:04PM -0500, Rob Landley wrote:
> > The probability that a 128 bit random number will not be unique is 2^128.
> >  I _guarantee_ you have no conception of how _big_ that is or you
> > wouldn't be worrying about it.
>
> I used to work for a cryptography company; I actually do understand this
> kind of scale just fine. I just don't trust rand(). :-)

Neither do I, that's why I used the system random number generator built into 
the Linux kernel.

(Insert long discussion here about embedded systems with insufficient entropy 
sources that don't preserve entropy across reboots, and how you can use 
/dev/random instead so people get hangs and their system randomly fails in the 
field instead.  By the way, did you _read_ old_e2fsprogs/gen_uuid.c?  Look at 
the function on the bottom and trace your way back up, it uses 
"uuid_generate_random" in _preference_ to the "assemble various system 
information and hope it's unique" method.)

Rob
-- 
Latency is more important than throughput. It's that simple. - Linus Torvalds