A dictionary definition of the word virtual is very close to being something without actually being it. And we will find, when we create virtual machines and virtual servers, that we create something that is very close to an actual computer without actually being a computer. Another dictionary definition is being such in power or effect, though not actually such.
And this is one of the goals of our virtual machines, to have the same power and effect as a physical machine, though they are not actually a physical machine. Continuing to define the word virtual and now more in computer terms, virtual is the opposite of physical. And in the common terminology these days amongst engineers, when you want to discuss a machine that is not virtual, you say it’s a physical server. These virtual servers exist only in the memory of a computer. There are no physical components for us to touch or see…
Organizations have many challenges of maintaining desktop computers. They have to troubleshoot unique set ups if every user has a different desktop computer. Different hardware, different operating system, different software, that can make troubleshooting scenarios much more difficult. There’s a constant race to upgrade applications and that can be very labour intensive, if you have to manually walk to every single desktop, put in a disk, and do an upgrade.
That is very time-consuming and it seems like as soon as you finish one upgrade, now it’s time to upgrade a different application. And then there’s the hardware of the desktop computer. It’ll need to be refreshed periodically, either upgraded or buy a whole new machine. Some of these challenges overcome by using Virtualization, particularly a technique called virtual desktop infrastructure, or VDI. In a VDI scenario, a central server pushes a VM to each user. So when a user comes to their PC in the morning and they log in, the server will create a copy of the VM and it will be pushed to their local machine.
Most of the processing on that VM will typically occur remotely. So even though the user sees the VM on their local PC, the virtual processor is actually running on the server from which it was pushed. At this point the desktop is basically a dumb terminal. It’s a keyboard, mouse, and monitor, but all of the processing is going on remotely. When a user leaves for the day and logs out, a copy of that VM is not saved. Any document saved to the desktop would be lost. Therefore it’s very important for users to save their documents to a network drive.
An example of VDI is call center. They went with a VDI solution. They were able to use one virtual machine for every user. So every single employee, when they sit down at their computer, they get a copy of this virtual machine. That means the help desk only ever has to troubleshoot one situation. Everyone’s running the exact same operating system and the exact same software. It also means that if there is a problem on one of these virtual machines that would be very difficult to fix, you have the option of deleting just that copy of the virtual machine and providing to the user a fresh copy from the original image.
So the call center was able to accomplish their goal of reducing troubleshooting. They also found that they reduced the administrative effort of upgrading applications. They no longer have to walk around to every single PC to upgrade an application. They really just have to upgrade it once on the virtual machine, and the next time a user logs in, they get a fresh copy of that virtual machine with the upgraded application. They also found that it reduced their hardware costs. Now, all of the desktop machines are low-cost dumb terminals.
They did have to make an investment in a pretty nice server to serve up these virtual machines, but that cost was lower than the cost of all of the PCs. And it also allowed them to expand quickly. If they want to hire five or ten or fifteen new employees, all they have to do is go out and buy that number of dumb terminals, connect them to the network, and as soon as someone logs in they will get a copy of the virtual machine ready to go. Many of these benefits were magnified because everyone was using the same VM.
And in some organizations, that is certainly possible. In other organizations, you might need to create two or three different versions of the VM, because different users will have different needs. That’s okay. If you get into a situation where every single user has really unique and different needs and therefore you’re creating a new virtual machine for every single user, then VDI may not be the best solution for you.