Check best practices and environment and hardware here as well as the 'known issues'... and note that the vmware probe should be installed on a hub NOT a simple robot.
1. Launch the probe with no VMs configured using 1GB RAM. i.e 1 GB for base probe with no devices 2. Get a count of the number of VM's on the vCenter you want to monitor. 3. Based on the count of VMs in the vCenter, add 330 MB per 1000 VM's. 4. For example, if you have 3000 VMs in your vCenter, then you need 1 GB + 1GB (i.e. 330MB*3) .That is your maximum memory you need for the VMware probe per vCenter. The rule-of-thumb to be followed is:
(1 GB + 330 MB, per 1000 VM = Maximum RAM needed.)
Set your java heap min/max accordingly in the vmware probe.