Native multipath across multiple subsystem NQNs

[Christoph Hellwig]

On Sat, Feb 12, 2022 at 01:22:21PM -0800, Keith Busch wrote:
> On Sat, Feb 12, 2022 at 07:34:22AM +0100, Christoph Hellwig wrote:
> > The answer is neither.  The fact that NVMe with ANA required namespaces
> > to be be attached to the same subsystem is good and important.
> > TPE 4034 is retrograde and completely broken in this respect and should
> > have never been ratifier.  Please fix your storage system to export
> > virtual subsystems like everyone else and don't break the nice NVMe
> > architecture.
> 
> If anything, the driver could check for duplicate namespace identifiers
> across subsystems so that we could warn about or prevent exposing them.

Yes, this has actually been something I've been wanting to do for a long
time.