Storage Networking Fundamentals: An Introduction to Storage Devices, Subsystems, Applications, Management, and Filing Systems

The Necessity of Redundancy in Storage Networks

Redundancy is the primary principle supporting data protection and high-availability computing. Without redundancy there would be no way to recover from even the smallest mistake or component failure, such as the failure of a disk drive. A data center that has tens of thousands of disk drives should expect to have regular drive failures in the course of normal operations. Without data redundancy, each of these disk drive failures could be catastrophic.

Of course, device failures represent only a part of the overall requirement for data redundancy. Large-scale disasters also occur and need to be protected against. The distance capabilities of storage networks mean it is possible to store redundant ...