Virtualisation technologies: what you need to know
Virtualisation technology is widely used in IT and technical environments. Virtual machines (VMs) allow multiple tasks to be performed while optimising the use of resources. In most companies and organisations, virtualisation has become essential, and system and virtualisation engineers, administrators or virtualisation consultants are particularly sought after. Find out everything you need to know about virtualisation technologies and which ones are most used by professionals in this article.
What is virtualisation?
Definition and aspects of virtualisation
Virtualisation is the process of running a virtual instance of a computer system on an abstraction layer (software) of real hardware. To function, this virtualisation process relies on two essential components: the hypervisor and the virtual machines.
Virtual machines or VMs are, as the name suggests, virtual environments that simulate physical calculations and behaviour, but in software. In concrete terms, it is a computer that runs on another computer. The VM thus has its own resources (CPU, memory, operating system, etc.) which are available in an isolated partition on its host computer.
The hypervisor is a software layer that installs, configures and coordinates virtual machines. It acts as an interface between the physical hardware and the VM and ensures that both the virtual machine and its host computer have access to the physical resources they need to operate. In multi-virtualised environments (with several VMs on a single machine), the hypervisor ensures that the VMs do not interfere with each other, particularly in terms of memory or calculation areas.
The term virtualisation is also frequently used in IT to refer to the simultaneous running of several operating systems on an IS. However, it is not only OSes that can be virtualised.
The different types of virtualisation
All components of an IT infrastructure can be virtualised. System architects and other IT professionals are regularly called upon to implement:
desktop virtualisations including Virtual Desktop Infrastructure (VDI) which allows multiple desktops to be run on virtual machines available on a central server;
processor virtualisations that allow a single CPU to be split into multiple virtual processors for VMs;
storage virtualisations that allow all storage devices on the network to be accessed and managed as a single device from a shared pool;
network virtualisations to design a software view of the network that an administrator can then use to manage the network from a single console. This type of virtualisation includes software-defined networking (SDN) and network functions virtualisation (NFV);
data virtualisations that created the software layers between the systems storing the data and the applications accessing it;
application virtualisations to run the application software without installing it directly on a physical machine;
graphics processing unit or GPU virtualisations that allow one or more VMs to use a single GPU. This type of virtualisation is particularly useful for optimising the performance of graphics or mathematical applications or artificial intelligence algorithms;
cloud virtualisations using infrastructure as a service (IaaS), platform as a service (PaaS) and software as a service (SaaS).
The benefits of virtualised environment
Full use of resources
The primary use of virtualisation in an enterprise setting is to be able to host multiple VMs on a single server. So if an organisation wants to develop multiple applications, it can simply deploy more virtual machines instead of investing in additional physical servers. In addition to reducing costs, it increases profitability by using the physical equipment to its maximum capacity.
Technically, adding a virtual machine is as simple as cloning copies of existing VMs onto physical hardware. The organisation's IS is therefore more flexible and better able to react to fluctuations in workload.
Virtualisation environments are isolated from their host operating system. This way, vulnerabilities and malware do not affect the physical machine. Virtual machines are therefore also useful for testing applications in a real environment before they are put into production.
A basis for cloud computing
Virtualisation is linked to cloud computing. Companies can deploy cloud native VMs and then migrate them to on-premises servers or host their own virtual machines in the cloud. IT developers can also create ad hoc virtual environments in the cloud to test their implementations.
The 5 most popular virtualisation software systems
Microsoft Hyper-V allows you to run multiple virtual machines that can be used on-premises or with Azure.
With Hyper-V, it is also possible to run several OSes (different versions of Windows, Linux, etc.) in parallel on a single physical server.
It is bundled free of charge with Windows Server 2008 and on OS Windows 8 and higher.
Architects, developers and other IT professionals can use it as a stand-alone product or as part of Windows Server.
Oracle VM VirtualBox
Oracle VM provides a simple, user-friendly environment for managing multiple VMs and operating systems (Linux, Mac OS X, Solaris, FreeBSD, etc.) on a single PC or server. The latest version of this software offers a "Memory Ballooning" system to dynamically manage the memory of each virtual machine.
Citrix Hypervisor is open source virtualisation software optimised for desktop, server and application virtualisation infrastructures. In addition, it includes a security solution with application isolation and protection against malware and zero-day attacks.
The Red Hat® Virtualization platform supports the virtualisation of resources, processes and applications. It is based on Linux and offers a number of integrations with other Red Hat tools such as Red Hat Ansible Automation Platform, Red Hat OpenShift, and Red Hat OpenStack Platform.
SolarWinds Virtualization Manager
Virtualization Manager is a VM management and monitoring tool. This monitoring includes performance testing, capacity planning options and predictive recommendations. The virtual machines managed by Virtualization Manager include those on-premises, in the cloud and in hybrid environments.
As an IT professional, what virtualisation software do you use? Which virtualisation technologies do you encounter most frequently in your projects and companies? Please feel free to share your feedback on the IT forum!