Re: [LSF/MM/BPF TOPIC] dispersed namespaces revisited

[Christoph Hellwig <hch@infradead.org>]

On Wed, Mar 23, 2022 at 09:17:58PM -0400, John Meneghini wrote:
> I agree with Christoph that the current conception of dispersed namespaces fundamentally breaks the NVMe storage object model.
> 
> However, there have been several ideas proffered at FMDS to fix this and I
> think people are willing to make changes to TP-4034 to redress this problem.
> 
> I think this is a topic that needs to be discussed at LSF/MM or ALPSS.

NVMeoF has been designed to support more than one "virtual" subsystem
behind a single port, and thus use the subsystem as a lean per-tenant
container including the ability to scale and migrate it over multiple
pieces hardware.  And ANA and Domains have made that even easier.

So really what we need here is a clear explanation of why this does
not work for the people that scream loud, and why brekaing fundamental
NVMe abstractions is the way to go.  This is the specific question I've
asked since the TPAR was proposed but it has simply been ignored.  And
no, dumb implementation with a lot of legacy baggage do not count.

The array vendors need to do their homework first.