Sizing and planning the VMware VI agent deployment

The number of agent instances that you can configure on a single system depends on the availability and utilization of resources on the system.

The following table categorizes the VMware environment into various sizes with the required Java™ heap size:
Table 1. VMware environment and Java heap size
VMware environment size Number of ESX servers Java heap size
Small environment A vCenter server that manages up to 125 ESX(i) servers and 300 - 1500 guests. -Xmx2048m
(2 GB)
Medium environment A vCenter server that manages between 125 - 250 ESX(i) servers and 1500 - 4000 guests. -Xmx4096m
(4 GB)
Large environment A vCenter server that manages between 250 - 500 ESX(i) servers and 4000 - 7500 guests. -Xmx8192m
(8 GB)
Very large environment A vCenter server that manages more than 500 ESX(i) servers and more than 7500 guests. -Xmx16384m
(16 GB)
To increase the heap size for the Java data provider, complete the steps that are described in Increasing the Java heap size.
For the agent instances to successfully monitor the environment, the server on which you install the agent, must have adequate memory resources to accommodate the data that is collected by these agent instances. A single instance of the VMware VI agent requires approximately 300 - 400 MB to monitor a small environment. See the following guidelines about the number of agent instances to be configured:
  • Use a single instance to monitor a single vCenter. Do not use the same instance to monitor multiple vCenters.
  • In a non-cluster environment, use a single instance to monitor a maximum of 8 small ESX servers (100 - 200 virtual machines in one ESX server). Do not configure multiple individual ESX servers under the single agent instance.
  • Use multiple agent instances of the VMware VI agent to monitor an environment that contains multiple vCenters. Before you configure multiple instances, ensure that you have adequate memory resources on the system where you install the agent.