Re: NetBSD 10.1 VPS became unresponsive

[Greg Troxel <gdt%lexort.com@localhost>]

Christof Meerwald <cmeerw%cmeerw.org@localhost> writes:

> VirtFusion is based on Linux KVM.

That I have heard hof.

> I am not sure about a missed interrupt (or even anything kernel
> related) - wouldn't that also affect pings and TCP connections?

If the disk interrrupts were missed, and network interrupts were ok, it
could be consistent.  I'm just guessing.

> To me it would feel more like maybe syslogd blocking on something
> (which might then also block anything trying to log something via
> syslog)?

I wouldn't expect syslog clients to block.

You also haven't described the machine.  If you're doing anything other
than setting YES in rc.conf to start things at boot, please explain.

Also, you could explain the history and frequency.  Did this arise
recently?

> In any case, any idea how to debug this? For now I have attached
> ktruss to syslogd, but I am not sure how often I might see this issue.

I would write a script to run ps alxw once a minute and save it to files
named by date +%s, and see if that results in interesting values in
wchan on the next incident.