VMware ESX 4.0 Update 1 and Later and vCenter Server 4.0 Update 1 and Later


vSphere Resource Management Guide : Managing Memory Resources : Administering Memory Resources

Administering Memory Resources
Using the vSphere Client you can view information about and make changes to memory allocation settings. To administer your memory resources effectively, you must also be familiar with memory overhead, idle memory tax, and how ESX/ESXi hosts reclaim memory.
When administering memory resources, you can specify memory allocation. If you do not customize memory allocation, the ESX/ESXi host uses defaults that work well in most situations.
You can specify memory allocation in several ways.