Purpose of virtual machines: Each Virtual Machine is like a separate platform, and the host PC is transparent to the end user. A virtual machine reduces the amount of hardware required. The hardware on the host computer is shared among several virtual machines. If a virus infects a virtual system, then it is usually limited to that specific virtual machine only.
Memory (or RAM) is the most important component when considering a host machine for virtualization. You need to have as much memory as possible onboard the host machine so that the virtual machines do not suffer from delays in performing routine tasks.
Access rights: One needs to have access rights to access network resources. Access rights is a generic term that grants permissions to a user, or to an application, to read, write and erase files in the computer. Access rights can be tied to a particular client or server, to folders within that machine or to specific programs and data files.
The following are the benefits of virtualization:
1. Virtual Machine Migration: It is easy to migrate a virtual machine to another host machine easily. It was not so when you install your operating system on a physical hardware as a stand alone OS. In the later event, you need to worry about hardware compatibilities, and adequacy of hardware resources, and even the compatibility of the operating system with the application being used. Moving and setting up a service on a dedicated machine is also labor intensive. On the other hand, a virtual machine may be migrated to another similar host OS in matter of minutes. This has enabled moving data between data centers very fast and affordable.
2. Decoupling of infrastructure and the server platform: The OS is decoupled from the hardware in a virtual environment, thus making it easy for the application developer not to worry about the infrastructure. At the same time, it enables data center operator to concentrate on the infrastructure performance and stability.
3. Instant Capacity: Virtualization enables elastic capacity to provide systems at a moment's notice. In the physical server world, it could take weeks to procure the hardware and integrate it with the existing system.