Re: domU memory exceeded =?=> spontaneous reboots

[Mike <debian@xxxxxxxxxxxxxxxxxxxxx>]

> In order to eliminate software (Xen) bugs, what is really needed is to
> break out a null modem cable.  Then hook up another computer or something
> else capable of functioning as a dumb terminal (ha! old tech to the
> rescue).  Serial ports are rather more effective for observing Xen
> panicing.

The motherboard doesn't have a serial port on its backpanel, just jumpers for
attaching one on the board.  And the case doesn't offer a place to mount a
serial port.

I'm not inclined to mess with the system to that degree at this point.  It's
functioning for now.

> Any possibility the computer's power supply is near its limit?  What
> could explain the sudden reset is processor usage goes up and pushes
> something power related beyond its limit.

I sent you a link to one blog post.  There's another post that covers stress
testing, which I think eliminates the idea of a power draw surge causing the
reboot.  There you can see that the system was running with all cores loaded.
The CPU is the main power draw in this system.  Yes, I added an NVMe drive
and a couple SSDs, but that's nothing compared to the CPU.  And currently,
the CPU load is quite small still.

In any case, I think I spec'd the system with an adequate PSU.

It also shows that the cores don't exceed 60C under load, which I think I
mentioned already.

> For the heck of it, you might try adding "cpuidle" to Xen's command-line.
> Then ensure the kernel module "xen_acpi_processor" is loaded.  If this
> helps then it could be power or perhaps processor heatsink.

I'll put that on my to-do list, if just for the power savings.


Thanks for thinking about it.  I was just recording the issue, not expecting
a resolution given the low level of the behavior.