A number of years ago, storage declared its independence from having to serve the needs of a single server. Today, storage systems, such as a disk array or a tape automation system, can accept input-output (I/O) requests from a number of server sources. In so doing, however, the direct communication between a server and the storage it controlled is severed. In its place is a network that links multiple servers to a storage system, hence the need for the term “storage networking.”

Storage networking can involve the use of a dedicated network, as in the case of a storage area network (SAN) or a local area network (LAN) for network-attached storage (NAS). In the case of a SAN in particular, the tradeoff for greater storage management functionality and better use of storage assets is the increased complexity of managing storage. For example, a SAN has, at its heart, a storage-dedicated switch, which requires management that is not required for storage that is directly attached to a single server.

The focus of the book is on helping the reader to navigate through this world of complexity effectively, to design resilient storage networks that reduce the complexity. A resilient storage network is one that is both flexible and scalable. Storage professionals realize that they cannot forecast all of the storage needs for all applications exactly, for example, which applications will require faster growth in storage, and by how much. Flexibility is the ability to adapt to unexpected business requirements without breaking the budget bank, and with incremental, not revolutionary, revisions to the storage infrastructure. Scalability is the ability to either increase the capacity and performance of a single storage system (vertical scalability) or aggregation of multiple storage systems, to act as if they had the combined resources of a larger system (horizontal scalability).

The book is divided into four parts, with two or more chapters per part. The first part discusses the reasons for building resilient networks, and covers the importance of information, as well as storage fundamentals. The second part goes into depth on networking with your storage. The discussion includes the basics of types of storage networks, as well as an in-depth discussion on fiber optics in storage networking. Metropolitan and wide area storage networks receive a fair share of attention, because storage networking is not necessarily just within a data center or a single building.

The third part goes into the heart of building a resilient storage network, including storage network design, storage network topologies, performance and capacity planning for storage networks, and protecting and securing storage and storage networks. The fourth part, on putting it all together, is essentially a series of examples that illustrate the principles examined in the preceding chapters. These examples range from small storage networking examples to large and high performance storage network examples.

The book is extremely well designed, from a reader’s point of view. Each chapter is prefaced by a “What This Chapter Will Do For You” page. This page contains a bulleted list of what the reader will learn in the chapter; this is an excellent idea, which should be more widely adopted. The book contains innumerable figures and tables. They are easy to read, provide the necessary level of detail, visually help prevent the book from suffering from information overload, and serve as good reference points for the ongoing use of the book after its first reading. The overall design helps with the formidable challenge of helping assimilate all of the fine granularity of detail that is required to communicate the necessary information.

A storage professional should find this book invaluable, and will probably read the book several times (as well as use the well-thumbed copy for reference at work, as necessary). Even though the discussion is at a level of detail appropriate for the storage professional, any information technology (IT) professional who wants to better understand the role of storage in a modern IT organization would find this book rewarding, even if all of the detail is not retained. That reader would gain a better perspective of the world of storage networking as it fits within the overall IT infrastructure. The high level of intelligibility, effective communication of concepts, and overall clear readability will help all readers accumulate a high level of working knowledge from the book.