VMware ESX Server offers many powerful features to Citrix administrators. Here is a glance at some of the most important features:
• Virtual machines may be administered centrally.You can manage an individual virtual machine or group of virtual machines remotely.
• Virtual machines are isolated.Each virtual machine operates independently of other virtual machines which run on thesame physical hardware. Any communication between virtual machines must beestablished explicitly. Crashing one virtual machine does not crash other virtual machines.Isolation is particularly useful for testing, controlling viruses and managing applicationsthat misbehave.
• Virtual machines can be configured to use hardware resources.Virtual machines offer complete control of hardware resources. You can configure virtualmachines running CPU-intensive applications to use one or two processors, and givevirtual machines with memory-intensive applications greater amounts of memory. In thisway, you manage the resources that applications use on a single physical machine tobalance the load between virtual machines, and take advantage of all processing powerand memory available.
• Virtual machines are easily copied and deployed.Once a virtual machine is created and configured, you can use it as a master from whichyou can create copies in minutes. The copies have the same operating system,configuration and applications, but have unique system identities.
• Virtual machines can be moved between physical machines.VMotion can transfer the entire system and memory state of a running virtual machinefrom one ESX Server machine to another. The transfer period is usually imperceptible tousers. This feature is useful for testing, deploying software (including Citrix and operatingsystems) across a large organization, and maintaining hardware without interruptingservice.
• Machines can be consolidated.Existing machines, including their various operating systems, can be virtualized andconsolidated onto fewer physical machines, maximizing resource usage and freeing upmachines, physical space and power.