By default, a PC has one operating system. If you use the PC, you use that operating system. With multiboot it is possible to install multiple operating systems on one PC, but you cannot use them simultaneously, which greatly limits the possibilities of use. Virtualization does offer that possibility. With virtualization you use the power of modern computers to the maximum. What virtualization is, how it works and how you use it, we tell you in this article.
When you think of multiple operating systems on one PC, you quickly think of a dual or multiboot system. On a multiboot system, after the first operating system, you install a second or third (and perhaps fourth) operating system each separately on the PC. Then each time you start the PC, you decide which operating system you want to use next. Multiboot has the advantage that the active operating system can use the full computing power of the PC. But it also has an important limitation: you never have multiple operating systems running at the same time, always just one. If you want to do something in a different operating system, you have to close the current session and restart the PC. Information that you want to transfer from one operating system to another must first be saved and made accessible. Virtualization does not have these disadvantages, with virtualization the operating systems are active at the same time.
01 What is virtualization?
With virtualization, you first just install one operating system on the PC. This is called the host operating system. You then install a virtualization layer within that operating system, the virtual machine manager. This software layer adds the ability to provision virtual machines on the PC. A virtual machine is a software imitation of a computer that uses the hardware of another physical computer through the virtualization layer. You can start such a virtual machine and see the bios start just like with a real computer, after which you can install an operating system. In the virtualization layer you usually configure per virtual machine how much of the computer memory it gets to use, how much processing power of the processor and how much storage space on the physical disk.
02 Why virtualize?
The additional possibilities created by virtualization are countless. For example, because host and guest operating systems are running simultaneously, you can run multiple versions of an operating system simultaneously on the same computer. For example: Windows 10 side by side with Windows 7 or 8. Or two versions of Windows 10 side by side. But you can also use operating systems like Linux, OpenBSD, Solaris or the ancient MS-DOS. You can still use programs that only work on one specific operating system at the same time as your 'normal' applications. By extension, you can continue to use outdated software that is no longer compatible with a newer version of the host operating system. This can even prevent you from having to buy an expensive new license for newer versions when the old one still works just fine.
Virtual machines are also ideal for testing unknown programs. The software you use in the virtual machine cannot interfere with the operation of the host operating system. So it is safe to use software within a virtual machine, although antivirus and updates are equally necessary there.
Forms of virtualization
The form of virtualization mentioned here, where your operating system uses a virtualization layer with another operating system on top of it, is called host virtualization. The weakness of this virtualization approach is its dependency on the underlying host operating system. If something goes wrong there, all virtual machines fail. That is why this form of virtualization is popular for short-term testing and hobby work. More professional environments tend to opt for something called bare metal virtualization, such as VMware ESXi, Citrix XenServer, Linux KVM, and Microsoft Hyper-V Server. There is no separate operating system under the virtualization layer, but the virtual machine is the operating system and virtualization layer in one. This is more efficient and reliable.
03 What hardware is needed?
Virtualization has two ingredients: virtualization software and a physical computer. This computer mainly counts the processor, working memory and storage. However, it really doesn't have to be a very expensive and elaborate computer. A computer of a few years old with 4 GB of memory and a few gigabytes of free space on the hard disk is sufficient, but you can run fewer virtual machines at the same time. Because although the virtualization software neatly distributes the computing power of the computer, the host operating system always claims some of the computing power and memory, and also loads the hard disk. In practice, the amount of internal memory is especially crucial: 4 GB is just on, 8 GB is fine, 16 GB or more is perfect. In addition, preferably use a recent 64-bit processor and an SSD instead of a hard disk (with at least a few tens of gigabytes available).
04 What software is needed?
The range of virtualization programs is not very large. First of all, there is VMware, which offers two of the same programs for both Windows and Linux: Workstation Pro and Workstation Player. Although the name suggests otherwise, the Player also allows you to create virtual machines. In addition, Workstation Player is free for non-commercial use. For macOS, VMware offers the paid programs Fusion and Fusion Pro. Parallels Desktop is also a paid option for macOS.
If you want to use virtualization for free, then there is VirtualBox in addition to VMware Player. VirtualBox is open source and available for Windows, Linux, Solaris, OpenSolaris and macOS. VirtualBox has the least hardware requirements, but is less extensive and less good at complex graphics and games. Finally, anyone with a 64-bit version of Windows 8 Pro or Windows 10 Pro has the option to add the Hyper-V component to the Windows installation. This also makes it possible to set up virtual machines.
05 Select software
Are you going to virtualize on Windows, macOS or Linux? Do you need more or less advanced features? Do you want to pay for it? Do you need a lot of graphics computing power? These are important considerations.
If you want to use the same virtualization on every operating system, VirtualBox is the only choice. If you want more advanced functions and better graphics performance, the other programs are more suitable. On macOS, the choice between VMware Fusion, Fusion Pro or Parallels Desktop is mainly based on price and possible preference. On Windows, VMware Player will do for most things. If you want the most advanced options, you can consider VMware Workstation Pro, but with a price of 275 euros that program is not cheap.
Although some combinations are possible, in practice we do not recommend having multiple virtualization programs installed on one PC at the same time.
Download software
You can safely download the various virtualization programs from the following sites.
Oracle VirtualBox
Parallels Desktop
VMware Workstation Pro
VMware Workstation Player
VMware Fusion/Fusion Pro
06 VirtualBox and VMware Player
In this article we will focus further on the two free virtualization programs for Windows: VirtualBox and VMware Player. But whichever program you use: the steps as described are in all cases very similar in all programs. The installation always has few options, the default settings always lead to a working product.
Creating a new virtual machine is done in all programs with a wizard. The wizard ensures that all important configuration options are set. Click in VMware Player on Create a new virtual machine. The first thing you need to do is indicate where the operating system you want to install in the virtual machine is located. If this is a real CD or DVD, please choose Install disc and insert the CD/DVD into the DVD player of the computer. If you don't have a real disk, but you do have an ISO file, that will work fine too. Then click Installer disc image file (iso) and select via Browse the iso file (confirm with Next). Player now adapts the rest of the installation wizard to the operating system to be installed. With Windows you can already enter the license key and create an administrator account complete with password. click on Next and give the virtual machine a name and a location on the hard drive.
07 Virtual Disk
The next step in VMware Player is to create the virtual disk. You can save the virtual machine on your system as one large file or a series of smaller ones. You can adjust the size of the virtual disk yourself, but do not make it too small so as not to run out of space in the virtual machine later on. Moreover, the space is not immediately taken up completely, the size you specify is the maximum size. click on Next, you will now see an overview of the settings for the virtual machine. If these are OK, click on Finish to create the virtual machine and install the operating system.
