If you’re going to troubleshoot headless with only network accessibility (no local console on either serial or vga) then you’re a bit limited. Your only source of information is likely to be whatever system logs get entered before and during the event.
Make sure you enable socklog, or install another syslog server and enable that, since most of the services you’re probably interested in would use syslog facilities by default rather than their own log files. (primary way of going through socklog logs would be svlogtail)
Things that are hard to tell without further investigation:
- Could the network and network services be failing while the server itself is still running?
If so, then you might find an error in the system logs related to failing services or network.
If a kernel/driver error is taking out your network but allowing the system to keep running, that would probably show up in the logs. (
svlogtail kernel would be your best bet there)
- Could the system be totally frozen due to a kernel panic? Might be harder to tell. Something severe could possibly completely hang the system rather quickly, preventing its entry into the logs…
At any rate, if you’re only checking after the fact (after you reset the system) then logs are the best thing you have to go by without attaching a console…
EDIT: picked up a link to the wiki on this thread (specifics for enabling socklog)