nguid for nvme over fabrics

[Sagi Grimberg]

> Hi,
> 
> I am trying nvme over fabrics, and found this: nguid is set to 0s by 
> default for all devices.
> 
> So, nguid can be same (0s in this case) for multiple devices. Is this 
> valid ?
> Also, same nguid for multiple devices could be set, by the above scenario.
> No errors/warnings from either the nvme initiator/target.
> 
>  From spec, I see this:
> Namespace Globally Unique Identifier (NGUID): This field contains a 
> 128-bit value that is
> globally  unique and assigned to  the  namespace  when  the  namespace 
> is  created.  This  field
> remains fixed throughout the life of the namespace and is preserved 
> across namespace and
> controller operations (e.g., controller reset,  namespace format, etc.).

We generate a UUID (which can be overwritten by the user)