[CentOS] How to determine why a server is not responding

Thu Apr 11 16:02:55 UTC 2013
Dale Dellutri <daledellutri at gmail.com>

On Thu, Apr 11, 2013 at 10:36 AM, nan del bosc <nandelbosc at gmail.com> wrote:

> Hi to all!
> We're using CentOS 5.5 64bits for our Plesk 11.
> This week we had the following problem 3 times...
> Suddenly, the server stops responding in all services (SSH, Apache,
> Postfix, ...) but ping works!
> After wait a few minutes (or 2 hours some times) the server continues
> unresponsive until we reboot. After reboot we search on /var/log/messages
> but cannot find useful information...

> What can we do? what can we test?

Are you running  sysstat / sar ?

Perhaps the sa / sar database that's left after reboot can show if some
was over capacity.