VMware ESX Command line Management
This documentation describes the concepts, tasks, and commands that you use to administer your virtual environment through the command line. vSphere provides several command-line interfaces that you can use to automate common tasks that you perform to deploy and support your virtual datacenter. For example, you can use vSphere command-line actions to configure and manage storage for the ESXi hosts in your datacenter, set up networking for virtual machines, perform virtual machine power operations, monitor hosts, and many other activities
http://pubs.vmware.com/vsphere-51/index.jsp