Recommended home directory for nagios user

For DNS/DHCP, you can use the existing Nagios plugins from your Nagios server to check that they're DNS-ing and DHCP-ing properly. If your cluster's running on SLES, you should be able to install the Nagios plugins and NRPE on the SLES servers, then monitor that with check_nrpe on the Nagios box. That will let you check mount points, running processes, etc.

Your command definition is expecting ARG1 and ARG2 (for -w and -c, respectively), but you are not passing them in after check_vmfs in your service def's command line.

So the resulting command being executed by Nagios is something like "/path/to/check_esx3-0.5.pl -H 172.32.3.3 -u user -p passwd -l vmfs -w -c", which is why it's returning "error: here's the usage help" instead of what you expect.

You should either remove the -w and -c pieces from the command definition, or add some (I'm assuming) thresholds to your service definition. E.g., "check_vmfs!10!20" or similar.