On Tue, May 17, 2022 at 10:03 AM stan via users <users@lists.fedoraproject.org> wrote:
On Tue, 17 May 2022 07:46:09 -0400
Sam Varshavchik <mrsam@courier-mta.com> wrote:


And I had something like this happen when a power supply was going
flaky.  The voltages had drifted out of spec as it decayed.

I too have seen that.
 

SSH into the system to see if it responds?

If your network supports OvrC you can set it to notify you when a system
goes offline.
 

Tough problem to diagnose.

Agree (but an interesting challenge)

You can try to determine if the problem occurs randomly at a low rate rate (likely
hardware) or more deterministically after a long period of uptime by rebooting on 
a schedule.  Random issues are more likely hardware (e.g., power supply) while
deterministic is software (e.g., memory leak).

Getting crashdumps or console messages can help pinpoint the time.  Some
people have used a video camera set for time lapse to capture interesting 
details from the screen.

I've had systems that crashed when IT hit it with a periodic network scan.   I 
used the time correlation with network logs on a second system to determine the
cause (faulty implementation of SNMP).  You need a system watching the 
network and a way to pinpoint the time of the failure.

--
George N. White III