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What is Server Virtualization?
Server virtualization refers to a server that is running as a virtual machine. Typically, a server refers to both a physical machine
and the software running on it (i.e., a "mail" server or a "web" server). Due to increases in computing power, it has now become possible
to run multiple "virtual" servers on a single "physical" machine.
What is a Virtual Machine?
A virtual machine is a tightly isolated software container that can run its own operating systems and applications as if it were a
physical computer. A virtual machine behaves exactly like a physical computer and contains it own virtual (ie, software-based) CPU,
RAM hard disk and network interface card (NIC).
An operating system can’t tell the difference between a virtual machine and a physical machine, nor can applications or other computers
on a network. Even the virtual machine thinks it is a “real” computer. Nevertheless, a virtual machine is composed entirely of software
and contains no hardware components whatsoever. As a result, virtual machines offer a number of distinct advantages over physical hardware.
In general, virtual machines possess four key characteristics that benefit the user.
Compatibility
Just like a physical computer, a virtual machine hosts its own guest operating system and applications, and has all the components found
in a physical computer (motherboard, VGA card, network card controller, etc). As a result, virtual machines are completely compatible
with all standard x86 operating systems, applications and device drivers, so you can use a virtual machine to run all the same software
that you would run on a physical x86 computer.
Isolation
While virtual machines can share the physical resources of a single computer, they remain completely isolated from each other as if
they were separate physical machines. If, for example, there are four virtual machines on a single physical server and one of the
virtual machines crashes, the other three virtual machines remain available. Isolation is an important reason why the availability
and security of applications running in a virtual environment is far superior to applications running in a traditional, non-virtualized
system.
Encapsulation
A virtual machine is essentially a software container that bundles or “encapsulates” a complete set of virtual hardware resources, as
well as an operating system and all its applications, inside a software package. Encapsulation makes virtual machines incredibly portable
and easy to manage. For example, you can move and copy a virtual machine from one location to another just like any other software file,
or save a virtual machine on any standard data storage medium, from a pocket-sized USB flash memory card to an enterprise storage area
networks (SANs).
Hardware Independence
Virtual machines are completely independent from their underlying physical hardware. For example, you can configure a virtual machine
with virtual components (eg, CPU, network card, SCSI controller) that are completely different from the physical components that are
present on the underlying hardware. Virtual machines on the same physical server can even run different kinds of operating systems
(Windows, Linux, etc).
When coupled with the properties of encapsulation and compatibility, hardware independence gives you the freedom to move a virtual
machine from one type of x86 computer to another without making any changes to the device drivers, operating system, or applications.
Hardware independence also means that you can run a heterogeneous mixture of operating systems and applications on a single physical
computer.
There are a number of virtual environments to choose from-- some are even available for free!
There are a number of huge advantages to migrating your servers into a virtual environment. Please contact us via phone, web, or email
to learn more.
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