Troubleshooting server crashes

[Ilya Palagin]

Fraser Campbell wrote:
> Hi,
> 
> When a Linux server crashes there are often clear messages in the logs 
> indicating why ... out of memory and processes dying, file descriptors being 
> exhausted, whatever.
> 
> When a server crashes and absolutely nothing interesting is in the logs what 
> does a person do?  I generally suspect hardware problems but when a server 
Turn on the monitor to find out if there is a kernel panic. What 
actually happens when it crashes?

> has been rock solid historically I don't put a lot of faith in that and in 
> any case it's just a guess.
How old is it? Maybe it's time to clean contacts on SIMMs, run 
memtest86,  replace a power supply (electrolytic capasitors get dry in 
2-3 years), make sure fans are good, run badblock?

> 
> The server is completely up to date; postfix, apache, courier (imap & pop) and 
> ssh accessible to the Internet.  It also runs mysql (not Internet 
> accessible).  Server 1 minute load average is normally less than 0.1.
> 
> What approaches do you guys take for tracking these things down? For now I've 
> installed atsar to track resources, post crash (if it happens again) I can 
> hopefully tell if it's a resource issue.
> 
> Although google is a great resource for finding specific error messages I find 
> tracking down topics like this can sometimes be difficult.  A website that 
> collected and organized troubleshooting tips would be a great idea, if only I 
> had the time ;-)
Crashes of stable Linux distributions don't happen on regular basis, 
there is no need in troubleshooting tips website :-). Seriously - if one 
starts to experience problems having no recent soft/config changes in 
the Linux system, hardware must be checked. I've listed the most weak 
parts above.

Regards,
Ilya.

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