Storage Area Networks, or SANs, are a very hot topic right now. As IT shops need larger and faster storage systems the run into serious scalability problems with conventional ways of aggregating storage. Borrowing from the extreme success of LAN networking, the SAN idea contains within it great promise to change how we store and move around our data. However, as with all young technologies with great promise, implementors need to separate the hype from the reality, and to come to understand what problems this technology solves and how to understand whether it might be appropriate as a solution for one's own environment. Designing Storage Area Networks aims to provide the information necessary for the reader to understand this new technology.
Early on, the book provides introductory material on the topic and background on storage and networking fundamentals. Then, Clark briefs the reader on details of the Fibre Channel protocol. After this, the author discusses possible SAN topologies and Fibre Channel products. Really, these three chapters cover, in extreme detail, the nuances of Fibre Channel deployment. Fibre Channel has changed drastically since it was initially ratified as a protocol, and Clark does a good job going over the state of all things FC in today's networks.
We then hear a discussion on SAN troubleshooting and SAN management before we get into some case studies and commentary on the future of Fibre Channel. The book ends with some appendices, including a bibliography that is fairly sparse (although this is a new field) and a good glossary.
Designing Storage Area Networks focuses on the networking aspects of SANs rather than the devices to be networked. Specifics of disks, RAID systems, hosts, backup devices, etc. are barely mentioned. However, details of Fibre Channel fault management and network topology are presented in abundance. If one is looking for a buyer's guide for SAN products, look in periodicals that have a chance of being reasonably up-to-date. Clark has written something that will have a longer shelf life.
Even though this book is part of Addison-Wesley's Networking Basics Series, this is a densely written, comprehensive book. I don't expect readers will be able to work through Designing Storage Area Networks in a lazy afternoon. Do not be fooled by this book's small size, it is not a light book. As a consequence, Clark manages to be quite thorough in covering his topics.
On the down side, I believe that Clark often paints an overly optimistic view of the current state-of-the-art in the SAN world. He is a proponent of open standards, which I firmly believe in, yet barely mentions that there is no cooperation between vendors on an open standard for data sharing over SANs. He does mention that there is still some significant device (especially switch) interoperability problems, but, in my opinion, does a bit of a disservice to readers (and the industry) by not being more detailed and providing more incriminating evidence. Also, in his test cases, the author dismisses some some possibilities for non-SAN solutions to the problems he presents far more casually then they deserve. We can forgive Clark some evangelism, but at times he borders on being unfair. Finally, the author rails against HTTP based management as being insecure even if it is password protected but doesn't even mention that SNMP based security is generally even more insecure under casual deployment.
Overall, though, Designing Storage Area Networks is a very comprehensive book on the topic of how SANs work, and I recommend it to IT professionals looking for information on this topic.
Designing Storage Area Networks is a good book on how SANs work. Occasionally, I believe that the author's evangelism is a little stronger than is appropriate, and there are some places where I think the advice is a little misguided, but overall Clark has put together a solid work. Do not be fooled by this book's small size, it's information density is considerable.
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