Since a couple of month I have problem with stalling programs. That is namely Webmin and Usermin (several times a day) and sometimes Postfix and Dovecot.
Since I didn't manage to find the root or the problem I installed Monit according to this site:
http://www.howtoforge.com/server-monitoring-with-munin-and-monit-on-cent...
I did following config:
[code:1] set daemon 60 set logfile syslog facility log_daemon set mailserver localhost set mail-format { from: Monit@example.com } set alert just_me@example.com
check process postfix with pidfile /var/spool/postfix/pid/master.pid group mail start program = "/etc/init.d/postfix start" stop program = "/etc/init.d/postfix stop" if failed port 25 protocol smtp then restart if 5 restarts within 5 cycles then timeout
check process dovecot with pidfile /var/run/dovecot/master.pid group mail start program = "/etc/init.d/dovecot start" stop program = "/etc/init.d/dovecot stop" if failed port 25 protocol smtp then restart if 5 restarts within 5 cycles then timeout
check process usermin with pidfile /var/usermin/miniserv.pid start program = "/etc/init.d/usermin start" stop program = "/etc/init.d/usermin stop" group misc if failed host 127.0.0.1 port 0000 type tcp then restart depends usermin_init
check file usermin_init with path /etc/init.d/usermin group misc
check process webmin with pidfile /var/webmin/miniserv.pid start program = "/etc/init.d/webmin start" stop program = "/etc/init.d/webmin stop" group misc if failed host 127.0.0.1 port 20000 type tcp then restart depends webmin_init
check file webmin_init with path /etc/init.d/usermin group misc[/code:1]
So far everything works fine and keeps alive.