Re: Xen hangs (NetBSD 7.0.1, amd64, Xen 4.5.3)

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Mon, Oct 17, 2016 at 04:44:41PM +0100, Alaric Snell-Pym wrote:
> 
> On my Xen box, I sometimes get a state where any "xl" command will just
> hang (in such a way as to not respond to SIGTERM, SIGKILL, or even a ^Z
> at the shell). Existing domUs are still running fine and can talk to the
> network and their xbd disks and *existing* xl console sessions, but I
> can't start new ones, or open new console connections.
> 
> xenconsoled and xenstored are both running (well, processes with those
> names exist and are in the "select" state according to top); all my xl
> processes are in state "tstile", and when I had a look this time, there
> were two xenstore-rm processes and a xenstore-read around, also in the
> tstile state:

this means that they're all stuck on a lock.
The first thing would be to use ddb (or crash(8), if this works on Xen)
to find where in the kernel these processes are stuck.

The next step would be to which which process is actaully holding the lock
(this one is probably not in tstile state)

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--