[CentOS] CentOS 3.5 system hanging

Wed May 31 23:15:17 UTC 2006
Les Mikesell <lesmikesell at gmail.com>

On Wed, 2006-05-31 at 17:42 -0400, Mark Belanger wrote:
> Our very large and very complex application is running on
> CentOS 3.5 and Solaris.   The CentOS machines are hanging
> about once per day.  By "hanging" I mean the system is
> completely unresponsive either from the console or remotely
> via ssh.   Totally locked.

If you have a large amount of swap space configured you may
be consuming enough RAM that the swap activity never catches
up with what the system needs.

> Does anyone have any tips for troubleshooting this sort
> of problem?

Let 'top' run on the console so you can see what was going
on when it stopped.   Also, install sysstat if you haven't
already and run 'sar -A' to see the saved periodic snapshots
of system resource use.   You might also enable snmp and run
something like cacti to monitor and graph cpu and memory use
to see if you can find a pattern to the activity (like a memory
leak in your application).

-- 
  Les Mikesell
   lesmikesell at gmail.com