Re: [PATCH]: xl: use libuuid to generate random UUID's

[Jeremy Fitzhardinge <jeremy@goop.org>]

  On 08/10/2010 03:44 AM, Ian Campbell wrote:
> On Thu, 2010-08-05 at 03:27 +0100, Jeremy Fitzhardinge wrote:
>> On 08/04/2010 07:19 PM, Ian Pratt wrote:
>>> The best approach is to generate locally administered MAC addresses
>> hence giving us 46 bits of freedom rather than XenSource registered
>> OUI addresses which have just 24 bits -- collisions will be *much*
>> less likely. Further, it's best not to generate random addresses every
>> time, but to derive the MAC address from a good hash of the VM UUID
>> and the NIC number so that they are deterministic.
>>
>> Yes!  I've been doing that manually (where my hash is '+'), but its
>> irritating to keep doing over and over.
> Where I care about a stable MAC I use
> 	vif = [ 'mac=xx:xx:xx:xx:xx:xx' ]
> in my domain config file. AFAICT that is the only 100% reliable way to
> get a stable MAC address since the other schemes all have some corner
> case or other...

I always manually set a uuid in the domain (well, uuid-gen), and I'd 
like the mac to be derived from that.

     J