Virtual Machines… Are They Real?
Yes, virtual machines are real and
they can provide your business with some real advantages.
Let’s start with a physical computer.
A typical small business may have three or four servers and 20 to 30
pc’s. These are physical boxes with an operating system, say Windows
Server 2003 or Windows XP. In the physical world, there is only one
operating system loaded on each box.
Many years ago, Citrix and Microsoft
pioneered the ability to present users with their own set of application
icons or even a desktop using just one server. This was an early form of
Fast forward to the present and what
you find is the ability to have one or more complete virtual computers
running simultaneously on just one physical computer! By ‘complete’ we
mean it boots up like a pc, it has its own operating system, it has its
own user security, etc. It simply displays in its own window on the host
There are some distinct advantages to
employing the use of virtual machines. A virtual machines (VM) is stored
in one big file. This means that you can backup a VM and more
importantly restore a VM just as easily. It often takes close to a day
to restore a physical server depending on the quality of the backup.
With a VM, it takes a fraction of that time.
Here are just a few examples of how
VM’s can be used. 1) You are testing out some new software and don’t
want to interrupt users on a production server because of reboots and
tricky integrations. A virtual machine runs in a ‘sand-box’ which is
completely isolated from everything else. 2) Downtime for one or two
days is not acceptable if one of your servers crashes. VM’s are used as
part of the overall disaster recovery plan. P2V - physical to virtual –
is the process of turning a physical computer (server or workstation)
into a virtual one. Should the real server crash, being able to bring it
back up quickly in a virtual machine will keep people working. While you
wait for parts for the real server, employees can connect to the VM. Any
work done on the VM can be saved and move back over to the physical
server once it is up and running again. 3) You want to make better usage
of your hardware expenditures and consolidate several existing servers
onto one physical computer. In one recent Beachwood engagement, the
client was able to shut down four old computers and put them all on one
new server with one VM. 4) You have Windows Vista on your notebook pc
but need to run an application that is only compatible with Windows XP.
You can set up a VM on a desktop or notebook pc just like you can on a
true server computer.
Virtual Machines are not perfect and do require substantial resources on
the Host machine which is the physical computer and native operating
system. On one server we deployed recently, we configured it with 12 GB
of high speed RAM along with fast SAS drives.
Microsoft’s new Server 2008 operating
system has a feature called Hyper-V that controls the use of virtual
machines. Citrix and VMware have excellent offerings as well. When you
purchase Microsoft Server Standard Edition you are licensed to use that
same operating system in one VM. With the Enterprise Edition, you are
licensed for four VM’s. In effect, you can now have 2 or 5 servers for
the price of one.