nguid for nvme over fabrics

[sim@linux.vnet.ibm.com (Narasimhan V)]

On 2018-03-23 00:32, Sagi Grimberg wrote:
>> 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)

Shouldn't it be unique ?
I have instances where for NVMef, multiple devices can have same nguids.
Which component should be responsible to generate nguid in NVMef ?


-- 
Regards
Narasimhan V