What are the system requirements for VM Ware?

Steelgate must be installed on a supported operating system. The machine where Steelgate is installed must have connectivity to either the vSphere server or the ESX(i) server. Steelgate can alternatively be installed on the vSphere server, or on a Virtual Machine. Version 4.0 and 4.1 of ESX(i) and vSphere licensed with the vStorage APIs are the currently supported versions of software that the VMware plug-in for Steelgate will communicate with. In order to do incremental or differential backups the communication must go through vSphere. The machine that has Steelgate installed on also has to have enough local disk space to temporarily hold all the Virtual Machines that you want to backup in one backup job.
Backup does not operate on a free VMware license.