In simple terms, virtualization offers a way to help consolidate a large number of individual machines/servers on one larger server(s). Virtualization allows multiple virtual machines/servers, with heterogeneous operating systems to run in isolation, side-by-side on the same physical machine.
Each virtual machine/server has its own set of virtual hardware (e.g., RAM, CPU, NIC, etc.) upon which an operating system and applications are loaded. The operating system sees a consistent, normalized set of hardware regardless of the actual physical hardware components.
How does virtualization work
Virtualzation is a host application or a server application that run on a server. These server(s) have an operating system installed like Microsoft Windows Server or a Linux based operating system. Installed on the operating system is the virtualization software like VMWare Virtual Server, VMware ESX/GSX Server,Solaris VirtualBox,XEN or Microsoft Virtual Server. This software is the management console for all virtual machines/servers.
When creating a new virtual machine/server, the management console will ask some key questions like:
- What operating system is going to be installed?
- How many processors are required for the virtual machine/server?
- How much memory to allocate to the virtual machine/server?
- The type of network interface card required and how it will connect to your physical machine?
- What kind of hard drives are required? (i.e, IDE or SCSI) and How many hard drives are required and their size?
Hardware like the CD-ROM, floppy disk drive, the USB, serial and parallel ports are automatically connected to the physical hardware. Ideally, your virtual machine/server will share similar characteristics to your physical host machine.
You can have multiple virtual machine/servers running on a physical host server in total isolation. This means if you have a virtual machine/server crash, none of the other virtual machines/servers will be affected. Virtual machines/servers and applications can only communicate over configured network connections.
The other advantage of utilizing virtualization is the ability to take snapshots or to roll back changes that you have done which may have compromised the way your virtual machine/server operates. After you have setup your virtual environment and you are happy with the way it operates you can take a snapshot so if you have a problem and your operating system crashes, just click a button and roll back to your previous snapshot and you’re up and running again in a matter of minutes.
Over the years virtualization has been used more as a test platform for IT based companies to test environments, software developed by software development companies, or to simulate a production environment.
How can virtualization help or benefit you
By operating a number of virtual machines/servers on a single server, IT managers can consolidate various environments on a smaller number of machines than would otherwise be possible.
Depending on your requirements, virtualization can help or benefit any business today. Companies are turning to virtualization to consolidate their infrastructure onto more powerful servers to save on hardware costs, or to give them the ability to run old legacy systems within a virtual environment. Virtualization helps businesses with scalability, security and gives better management of your current IT infrastructure.
Here are some benefits of using virtualization:
- Multiple applications and operating systems can be supported within a single physical host system.
- Servers can be consolidated into virtual machines/servers on either a scale-up or scale-down architecture.
- Computing resources are treated as a uniform pool to be allocated to virtual machines/servers in a controlled manner.
- Virtual machines/server are completely isolated from the host machine and other virtual machines/servers. If a virtual machine crashes, all others are unaffected and continue running. Data does not leak across virtual machines and applications can only communicate over configured network connections.
- Complete virtual environments are saved in a separate folder; easy to back up, move, copy or run on another server.
- Standardised virtual hardware is presented to the operating system – guaranteeing compatibility across all virtual machines.