3
Dunno about that XOOPS module, but we use a monitoring server with cacti which polls every 5 minutes if the server is up and running (it also monitors the apache and MySQL loads, disk space and alot more via snmp)
The downside is that you'll have to get a second server which performs those tasks.
link:
Cacti.netIf you are having problems setting it up from scratch, there is a linux distribution which not only beholds Cacti but also alot of other networking tools.
link:
EZcacti