How To Consolidate Servers With VirtualizationHow To Consolidate Servers With Virtualization

Step 3: Install the Guest OS software. Essentially, a Virtual Machine can be thought of as just another physical machine. For instance, you have to install an OS on each VM before you can load any application software and put the virtual server to work, just as you would on a physical machine.

The VM's OS is called the Guest OS because it resides on the physical machine's host OS. As I mentioned above, a VM can run a different guest OS than the host OS. You can create multiple VMs, each with a different guest OS. This is one of the main advantages of virtualization. It comes in handy when multiple servers are needed for different software applications, but hardware constraints or budget concerns won't justify multiple physical machines.

As you may imagine, your Virtual Machine requires a virtual CD/DVD drive to install from. You create this virtual drive by going into the Administration Web site and clicking on Virtual Machine. Next, click on Configure, and then click on CD/DVD.

Once here, you have a couple of configuration options. The easiest and quickest option: Simply capture the CD/DVD drive of the physical machine. But this may not be the best option, especially if you are running multiple VMs. Eventually, you could create contention for the drive among the multiple physical and virtual machines. To solve this problem in advance, configure the Virtual CD/DVD drive to read from ISO image files stored on a hard drive. That way, multiple VMs can attach to a single ISO image at the same time.

This option aside, the process of installing a Guest OS on your VM should be identical to that of installing an OS on a physical machine. This means you must reboot the VM and check for updates, etc., just as you would with a physical machine.

Step 4: Configure the Virtual Network settings in software. Virtual Machines have Virtual Network Interface Cards (Virtual NICs) that interface with the host machine's physical NIC(s). As many as four Virtual NICs per VM are supported by the Microsoft software, and as many physical NICs as you can load on the physical machines' host OS. The software driver that creates an interface with these is called the VM Network Services Driver.

You will first need to decide whether you require your VM to access its physical machine or other VMs on that physical machine. If you don't require any network connectivity, you won't need to configure a Virtual NIC at all (it is optional). But if you do wish to access the physical machine and/or other VMs on that machine, then you will need a Virtual NIC.

You can connect a Virtual NIC to either VMs only or to an external (physical) network. Once you connect to an external network, you also bring up the issue of network security. VMs will behave almost exactly like another physical machine on the network, complete with all the attendant security vulnerabilities such as viruses and hackers.

To manage your Virtual NICs, pull up your Administration Web site. Click on Virtual Networks, then click on Create. Next, type in a name for your Virtual NIC. Then select an available physical NIC from a drop-down list to attach. You can even type in some notes to remind yourself of this particular Virtual NIC's connections.

If you want to configure a Virtual NIC that you have already created, click on Virtual Networks. Next, click Configure. Then choose the Virtual NIC you wish to edit. The Microsoft Virtual Server 2005 R2 Standard Edition software has a built-in DHCP server to facilitate distribution of private IP addresses without creating network conflicts. Of course, you can use your own DHCP server, if you have one.

There you have it--a way to make better use of existing hardware, save money for your customers, and run multiple operating systems on the same hardware.

DAVID GILBERT is the owner of Appalachian Computer Systems, a West Virginia system builder that specializes in multiprocessor SCSI RAID servers.