Re: [PATCH v2 0/2] Adding per-controller timeout support to nvme

[Keith Busch]

On Wed, Apr 24, 2019 at 10:30:08PM +0200, David Woodhouse wrote:
> It isn't that the media is slow; the max timeout is based on the SLA
> for certain classes of "fabric" outages. Linux copes *really* badly
> with I/O errors, and if we can make the timeout last long enough to
> cover the switch restart worst case, then users are a lot happier.

Gotchya. So the default timeout is sufficient under normal operation,
but temporary intermittent outages may exceed it. It'd be a real
dissappointment if the command times out with an error anyway after
waiting for the extended time, but we ought to cover the worst case
time for a successful completion.