Distributed Systems

Chapter 1

3.2 Virtualization

Resource virtualization can be seen as a way to emulate computer architectures by creating new layers of communication interface. Computer systems are are usually divided that way; it starts on hardware level, then it scales up to machine instructions, and then to the operating system, system calls and programs APIs.

The concept of virtualization can be used in distributed systems primarily for a matter of portability, since different components have different architectures that need to be used. By creating different levels of abstraction, which are considered virtual machines, it is possible to use an intermediate level of abstraction that can be used by all the different components of a distributed system to communicate through, without compromising higher or lower levels of abstraction, which are needed for the inner functioning of each component.

The main reason for virtualization in distributed system is to ensure resource transparency, since, by emulation, the system can hide from the user the absence of harware resources that it seems to have.