We are running VirtualBox and phpVirtualBox for a few test servers, recently we have had stability problems on some of them, does anyone know of any remote monitoring tool (open source/free prefered) that can monitor Virtual Machines, a web (php) interface would be nice. It is normal Windows machines (mostly) so I guess some form of SNMP software would work?
I use Nagios for monitoring servers. The community has lots of information on how to configure Nagios with Windows servers, using NSClient++. This guide offers the information you need for Windows servers specifically.