The product installation couldn’t be easier. Simply install SolarWinds VM Monitor, provide the IP address or name of your ESX server as well as that server’s read-only SNMP string, and output like you see below is generated.

n this capture from one of our live ESX servers, you can see that this machine has nine of 10 installed virtual machines powered on with one VM in a critical state due to CPU running at full-throttle. You’ll notice that it’s only the virtual machine’s CPU that’s running at 100% though. The ESX server CPU is still running at only 16% capacity.
To install and use SolarWinds VM Monitor, follow these steps:
1. Using a tool such as PuTTY, SSH to your ESX server and log in as the root user.
2. Allow SNMP traffic to traverse the firewall: esxcfg-firewall -e snmpd.
3. Enable ESX’s SNMP service: service snmpd start.
4. Download the SolarWinds VM Monitor.
5. Extract the contents of the downloaded ZIP file.
6. Double-click SolarWinds-VM-Monitor-v1.0.exe.
7. Run through the installation.
8. When prompted, provide the name or IP address of your ESX server along with the public SNMP string from your ESX server monitoring. The default string is public. If your public string is different, you can find it on your ESX server in the /etc/snmp/snmpd.conf file on the line that starts with rocommunity.
Source: blogs.techrepublic.com.com/datacenter/?p=1027