What is a virtual machine?
A virtual machine (VM) is a tightly isolated software container that can run operating systems and applications as if it were a physical computer. Although there is no hardware required for a virtual machine to operate, it still contains a CPU, RAM hard disk and network interface card (NIC), just like a physical computer.
VMs allow businesses to run operating systems that behave like a completely separate computer, either in an app window or on a desktop. Common uses of VMs include running software that requires a different operating system or to test applications in a safe environment.
What are the benefits of using a Virtual Machine?
Being able to use apps and operating systems without the need for hardware presents users with some advantages over a traditional computer. The benefits of virtual machines include:
Virtual machines host their own guest operating systems and applications, using all the components found in a physical computer (motherboard, VGA card, network card controller, etc). This allows VMs to be fully compatible with all standard x86 operating systems, applications and device drivers. You can therefore run all the same software that you would usually use on a standard x86 computer.
VMs share the physical resources of a computer, yet remain isolated from one another. This separation is the core reason why virtual machines create a more secure environment for running applications when compared to a non-virtual system. If, for example, you’re running four VMs on a server and one of them crashes, the remaining three will remain unaffected and will still be operational.
A virtual machine acts as a single software package that encapsulates a complete set of hardware resources, an operating system, and all its applications. This makes VMs incredibly portable and easy to manage. You can move and copy a VM from one location to another like any other software file, or save it on any storage medium — from storage area networks (SANs) to a common USB flash drive.
4. Hardware independence
Virtual machines can be configured with virtual components that are completely independent of the physical components of the underlying hardware. VMs that reside on the same server can even run different types of operating systems. Hardware independence allows you to move virtual machines from one x86 computer to another without needing to make any changes to the device drivers, operating system or applications.
What Types of Virtualization are there?
Virtual machines allow you to virtualise all the traditional components of data centres or IT infrastructure. The five core types of virtualisation include:
Hardware virtualisation, sometimes known as server virtualisation, allows hardware resources to be used more efficiently. With virtualisation, a single machine can run multiple different operating systems simultaneously.
With software virtualisation, we can create a computer system featuring hardware that allows one or more guest operating systems to run on a physical host machine. You can also virtualise applications and deliver them from a server to an end user’s device, allowing employees to access centrally hosted applications when working remotely.
By consolidating multiple physical storage devices to appear as one, storage virtualisation can increase performance speed, improve load balancing, and reduce costs. It’s also useful for disaster recovery planning, as virtual storage data can be duplicated and transferred quickly to another location, helping to reduce downtime.
Network virtualisation combines equipment into a single software-based virtual network, creating multiple sub-networks on the same physical network. It allows available bandwidth to be divided into multiple, independent channels, each of which can be assigned to servers and devices in real-time. Businesses can enjoy the advantages of increased reliability, network speed, security and improved monitoring of data usage.
Desktop virtualisation is one of the most common types of virtualisation. It separates the desktop environment from the hardware of a computer onto a remote server. Users will benefit from easy accessibility, better data security, ease of management and the cost savings of software licences and updates.
Use virtual machines as the building blocks of your virtual infrastructure
While a virtual machine represents the hardware resources of an entire computer, a virtual infrastructure represents the interconnected hardware resources of an entire IT infrastructure — including computers, network devices and shared storage resources.
Organisations of all sizes use VMware solutions to build virtual server and desktop infrastructures that improve the availability, security and manageability of business-critical applications.