On Fri, Jun 19, 2020 at 11:08:26AM -0700, Heiner Litz wrote:

quoted

Hi Matias,
no, I am rather saying that the Linux kernel has a deficit or at least
is not a good fit for ZNS because it cannot enforce in-order delivery.

FYI, the nvme protocol can't even enforce in-order delivery, so calling
out linux for this is a moot point.

How does it work in SPDK then? I had understood that SPDK supported
QD>1 for ZNS devices.
I am not saying that Linux is the only problem. The fact remains that
out of order delivery is not a good fit for an interface that requires
sequential writes.

quoted

The requirement of sequential writes basically imposes this
requirement. Append essentially a Linux specific fix on the ZNS level
and that enforcing ordering would be a cleaner way to enable QD>1.