Storage Networking Fundamentals: An Introduction to Storage Devices, Subsystems, Applications, Management, and File Systems (Vol 1)

Storage virtualization is one of the most important technologies in all of storage networking. This chapter examined the fundamental architectures, benefits, features, and risks involved with using storage virtualization.

Storage virtualization is a tool for manipulating storage address spaces and is implemented in two different types of products: volume management software and SAN virtualization systems. Volume managers work above the storage device driver layer, manipulating storage address spaces as they are presented to the host system. SAN virtualization systems are in the SAN between systems and storage. They perform their functions using proxy LUs and initiators to receive, interpret, and reinitiate I/Os that are received from host systems.

The main advantage of volume managers and SAN virtualization systems in SANs is the connection flexibility available in SANs. Many different types of storage can be combined in a number of ways to create reliable, redundant, super-scalable, cost-effective storage.