[PVE-User] base system restarted

[Matthew Caron]

On 07/04/2012 03:01 AM, Muhammad Yousuf Khan wrote:
> i am very new to Linux and i am sorry if it is a very beginner  level
> question i would request for your help and cooperation. i am using PVE
> 1.9  on 3 servers. one of my base system which was unexpectedly
> restarted or may be hanged (i dont know). but it didn't show the
> display then i press the power button it restarted and ping was also
> unresponsive.

Were the keyboard LED's flashing?

It sounds like you had a hard clock, crash, or kernel panic. The primary 
issue with relying on logs to find the problem is that often, the log 
message gets logged but then the system locks, so it never gets written 
to disk.

One of the old-school tricks on how to monitor this is to set the 
console to be on a serial port and hook it to a dumb terminal or another 
PC via serial cable. That way, the logged output goes to the other 
machine and is captured as soon as it is printed.

Indeed, it was/is quite common to have a machine called a "console 
server" which has a squidlike arrangement of serial cables going to 
serial ports on each server in a cluster. This gives one diagnostic 
output, plus a "hard" console dating from the days before KVMs. In 
modern times, this has been eclipsed by KVMs or remote management add-in 
cards (which often still appear to be a serial console, so if you have a 
machine with a remote management card, I would consult its documentation 
to see if it offers any functionality which may be useful here).

A corollary to this is to have it dump to a line printer, which are 
somewhat hard to find these days.


-- 
Matthew Caron, Build Engineer
Sixnet, a Red Lion business | www.sixnet.com
+1 (518) 877-5173 x138 office