What Is A Virtual Machine And How Does It Work?
In the past, I would need to use a physical computer for a single task, and for multiple tasks, connect several computer workstations to serve as physical servers. I was underutilizing the full processing power of the main server and others on the network, while working in a crowded, machine-filled room, worrying about periodic maintenance and high power consumption. A single computer can be converted to multiple virtual servers, using power more efficiently and getting more things done faster.
Enter virtual machines. A virtual machine is a software program that emulates the behavior of a separate computer. It can run separate operating systems and run applications in order to maximize the use of hardware resources without the additional costs of running standalone servers or computers.
Now with a virtual machine, I work more efficiently on a single computerand spend less on power. I can actually use Linux and Mac applications on a PC and execute multiple unsupported programs in a harmonious, platform-independent way.
How a virtual machine works
You can virtualize by “dividing” your computer, main hardware or physical server into multiple servers with the aid of specialized software. The virtual machine’s components comprise the hypervisor that communicates directly with the CPU and hard disk space. Essentially, VMs are classified as Process Virtual Machine, involving simple applications and System Virtual Machine, involving complex software.
Process Virtual Machine
Process Virtual Machine (or Application-based), works by acting as a runtime engine for specific language application. It is frequented by programmers. For instance, a software writer can design and deploy an application that can run on any platform, whether its hardware or software. This is how Java is made to streamline with all OSs because the writer converts the source programs to byte code in a way that can be manipulated by JVM (Java Virtual Machine).
JVM understands the byte code and converts it to the system-specific code that can be easily implemented, executing with the help of JRE (Java Runtime Environment). This type of VM usually comes with the applications the programmer needs.
Remember Gameboy games from Nintendo that use cartridges? They wouldn’t normally work on your machine without a game emulator like MAME. The emulator can read the code from a Gameboy cartridge and play the games on your machine without you needing to buy a Gameboy.
Other VMs of this mold include PVM (Parrot Virtual Machine), which serves as a runtime program to run Perl applications, and CLR (Common Language Runtime), which acts as a runtime engine for .NET-based programs.
Hardware Virtual Machine
Hardware Virtual Machine (or system-based) is a software emulation of a computer. This VM mimics the entire machine. The OS that is running on your computer is called the host while the OS running in the VM is called the guest. They are greatly associated with System Admin, Server admin operations frequented by regular end-users. Examples include VirtualBox, VMware Player, QEMU, Parallels, and Citrix Xen.
Uses of virtual machines
Why on earth should one play around with a VM?
Testing:Virtualization helps programmers to test an application on various OSs. Traditionally, you’d buy 7 different computers and install the different Operating Systems you want to test-run your program on (pretty expensive and time-consuming). However, with a virtual machine, you can emulate those 7 computers in a fraction of the time with spending a dime.
To learn a new OS:for instance, you have a Windows OS but want to learn Linux. Instead of partitioning your hard disk and installing the OS using GRUB – in which case you’d have to choose your OS every time you boot your computer, you’d simply allocate 5 to 20GB of your disk space to a virtual machine and work with a Linux OS there, hassle-free.
Cloud hosting:Let’s say you own a data center with a powerful server as your main hardware and you want to lease this resource to others. However, your prospective customer needs a part and not the entire server. You simply need to create a virtual machine and allocate a section of the server that is as powerful as they need it to be or are willing to purchase. In large organizations VMs helps realize cutbacks in expenditure to achieve economies of scale as owning dozens of smaller physical servers is much more expensive than owing one big server that can be virtually partitioned into dozens of smaller servers. The same can be said for smaller enterprises. For example, the cost of a Dell PowerEdge T330 Tower Server is over $1,200. Conversely, it costs a lowly $2.95 per month to get Bluehost Web Hosting.
Safety:because you need to protect yourself from that malevolent customer who comes at you with a curious zip file. And while you need to open the document, you don’t trust it completely. Opening the file in a virtual machine will only affect your “fake computer”, not your PC.
What are the most popular virtual machine apps that are out there?
There are a great number of VM applications out there for you to choose from:
VirtualBox: This is open-source and absolutely free. It works on Windows, Linux, and Mac OS X. It’s really a good place to start if you’re trying to have a feel of VMs for the first time. There are no nagging upgrade prompts too.
VMware Player:This is the VM line of VMware. You can apply it on Windows and Linux as a free, virtual machine platform. You are accosted to more advanced features when you upgrade to VMware Workstation program. Most VM users on the web start out with VirtualBox and those who found it dissatisfying tried VMware Player.
VMware Fusion: This is specially designed for Mac users as VMware Player is not available on Mac. VMware Fusion is sleeker than VMware Player.
Parallels Desktop:Mac users can enjoy this VM, especially if they wish to run Windows packages.
Other honorable mentions include KVM (Kernel Virtual Machine) by Linux, Hyper-V by
Microsoft – which is a professional and enterprise version for Windows 8 and 10 but is incompatible with Windows 7.
How do I install a virtual machine?
Setting up a VM program is really easy. And while we’ll discuss the installation procedure for VirtualBox, most VM packages allow you to install them pretty much the same way.
Step 1:Open your VM app and click “New” to create a new virtual machine.
Step 2:Select your preferred OS from the dropdown menu and click “Next.”
Step 3:The wizard will preselect some default settings for you, but you can alter them to your preferences over the prompts that follow on your screen. You’ll also be asked how much disk space you want to allot to the VM. Afterwards, click “Next” to continue. The wizard creates a virtual hard disk, and I recommend opting for the fixed disk size, because it is more responsive. In addition, it enables you to know how much disk space your VM is occupying. Click “create” to create your virtual hard disk.
Step 4:you’ll be sent back to the VM dashboard, and you can run your first VM by hitting “Start.”
Are there drawbacks to using a virtual machine?
Yes, there are. The performance of your VM will be greatly affected if you run high-end applications. Apps like Adobe Premiere Pro or Android Studio tend to lag your machine when executed in a virtual environment. Not to worry. If you’re scared about interfering with your hard disk and want to keep things normal, you can run a VM off an external hard drive.
Also, some legacy hardware such as specialist cards, connections and the like need bare-metal installation and may be difficult to virtualize.
Virtualization creates an administrative layer overseeing the normal network, infrastructure, and server stack. While this seems easy to understand, the user must have full knowledge of the whole stack in order to execute it effectively.
At enterprise level, there are also concerns about availability. If the work assets of a user are not made available for an extended period of time due to host server downtime, they’ll become disgruntled, and this is bad for business.
All in all, as virtualization technology continues to evolve, some of the above-mentioned concerns are fast-becoming a non-issue.