WHAT IS VIRTUALIZATION?
In simple terms Virtualization technology provides an environment (software layer) where multiple Operating Systems can run simultaneously on a single hardware package such as your personal computer or server.
Virtualization technology or software is generally referred to as Hypervisor.
WHY DO I NEED IT?
You may not! But if you’re reading this, I assume you are at least interested.
You can of course install and run multiple Operating Systems on a single computer without virtualization, however you are forced to load and use one Operating System at a time. If a different OS platform is needed for any reason, you will have to restart your machine to access it. To avoid this you may consider virtualization.
I used to install multiple systems on one PC (Linux, Windows, etc). But now I run a small Virtual Server and have all my favourite Operating Systems on one machine. I even have a NAS server running as a VM. The main advantage of virtualization for me, is that I can run and experiment on different technologies on the same hardware. I don’t need multiple servers or PCs and I can build one Affordable Virtual Server myself. For instance, I can simultaneously run Linux and Windows VMs and test if, for instance, SAMBA shares appear correctly on Windows clients.
The best feature, in my opinion, is the central and remote management of all of your Operating Systems in one place!
WHAT IS VMware ESXi?
VMware is a software company that develops virtualization software and tools. ESXi is the free-for-personal-use Hypervisor developed by VMware.
There are two types of virtualization software: bare metal, native or Type-1 Hypervisor and Type-2 or hosted Hypervisor. The difference, simply put, is that Type-1 Hypervisors have direct access and control of the hardware while Type-2 Hypervisors run as programs on other Operating Systems.
WHY VMware ESXi?
VMware is an industry giant and learning how to use its software packages and implement its Hypervisor technology is an advantage, challenge and good experience. Plus it is a native, bare metal or Type-1 Hypervisor available free of charge.
I have used some Type-2 Hypervisors in the past such as Oracle VirtualBox, Linux QEMU and Microsoft Client Hyper-V and they are viable options depending on your needs. However by running Type-1 Hypervisor, you are eliminating the middle man (Operating System) and reducing the extra overhead on your resources as well. This will make a noticeable difference on lower spec’d consumer hardware.
XenServer is an Open Source alternative that you can explore as well. But for the purposes of this multi-part article, we will stick to VMware ESXi.
I encourage you to try a few different hosted virtualization software to gain some practical experience and understanding of Hypervisors and Virtual Machines. Depending on the current Operating System you use, there are plenty of choices.
If you are running Windows 8, 8.1 or 10 Pro or Enterprise editions, then Client Hyper-V may be the easiest choice. Simply enable it via ‘Windows Features’ and start exploring by creating your first guest VM.
If your version of Windows Operating System doesn’t qualify for Client Hyper-V or you are using Apple OS X, then Oracle VirtualBox is a multi-platform solution. Download, install and explore VirtualBox.
If you are running Linux, then KVM and QEMU combination will provide a nice virtualization environment. Bear in mind that typically with Linux, you may have to get your hands dirty and do some troubleshooting.
In the next post I will discuss how to build an Affordable Virtual Server using well priced hardware available in the consumer market.