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 resource was over capacity.