sporadic CAM (all devices) outage on 11-stable, mps(4), ahci(4) and bhyve(8) involved. [Was: Re: mps(4) blocks panic-reboot]

[Harry Schmalzbauer]

Bezüglich Stephen Mcconnell's Nachricht vom 01.06.2017 20:55 (localtime):
> Take a look at PR 212914. Could that be the issue? It was MFC'd to stable/11
> with r309273 on Nov 28th, 2016.

Thanks a lot, but that's unrelated.
The "readded" phenomen wasn't true and last occurance of that
simultanious drives disappearance was 3 weeks ago (on r317xxx).
But it was before I completely got rid of unionfs usage.
Since I use(d) a panic-workarround-patch for unionfs, these deadlocks
could happen and I hoped that could be to blame for the quoted symptom,
for which I couldn't imagine any other cause yet.

Thanks,

-harry