HOW IT WORKS
Virtualization 101
IT organizations are challenged by the limitations of today’s x86 servers, which are designed to run just one operating system and application at a time. As a result, even small data centers have to deploy many servers, each operating at just 5 to 15 percent of capacity—highly inefficient by any standard.
Virtualization uses software to simulate the existence of hardware and create a virtual computer system. Doing this allows businesses to run more than one virtual system – and multiple operating systems and applications -- on a single server. This can provide economies of scale and greater efficiency.
The Virtual Machine
A virtual computer system is known as a “virtual machine” (VM): a tightly isolated software container with an operating system and application inside. Each self-contained VM is completely independent. Putting multiple VMs on a single computer enables several operating systems and applications to run on just one physical server, or “host”.
A thin layer of software called a hypervisor decouples the virtual machines from the host and dynamically allocates computing resources to each virtual machine as needed.
Key Properties of Virtual Machines
VMs have the following characteristics, which offer several benefits.
Partitioning
Run multiple operating systems on one physical machine
Divide system resources between virtual machines
Isolation
Provide fault and security isolation at the hardware level
Preserve performance with advanced resource controls
Encapsulation
Save the entire state of a virtual machine to files
Move and copy virtual machines as easily as moving and copying files
Hardware Independence
Provision or migrate any virtual machine to any physical server
Server Consolidation
Using server virtualization, a company can maximize the use of its server resources and reduce the number of servers required. The result is server consolidation, which improves efficiency and cuts costs.
It’s Not Cloud Computing
Cloud computing is not the same thing as virtualization; rather, it’s something you can do using virtualization. Cloud computing describes the delivery of shared computing resources (software and/or data) on demand through the Internet. Whether or not you are in the cloud, you can start by virtualizing your servers and then move to cloud computing for even more agility and increased self-service.