Creating documentation for your SAN is an important, but often overlooked, step in the production process. Comprehensive documentation provides a baseline for the SAN, and makes management and tuning easier.
How complete is "complete"? Brocade suggests a simple test. "The goal of documentation is to provide enough information for someone else to reproduce your SAN," the SAN vendor says in its discussion of SAN implementation. In other words, if you and your entire staff get hit by a a bus tomorrow, a storage professional completely unfamiliar with your system should be able to come in and replicate it using the documentation. That's a high standard, but meeting it will save you and your successors a lot of work.
Ideal documentation provides two levels of detail. The first is the overview that helps keep the user oriented and explains what is going on generally -- and preferably why. The second is the fine detail that lets a user trace the flow of data from point A to point B, with each step and spec spelled out along the way.
The first thing in the documentation folder should be a section of logical and physical diagrams of the SAN as installed, as well as the switch topology and host connections. These diagrams give a bird's eye view of the installation, and will probably be the most frequently used part of the documentation.
The documentation should include a list of all devices and the firmware versions for each device. It is also a good idea to have an additional copy of the firmware for each device included in the documentation.
Start your documentation with the cables. All the cables in the SAN should be clearly labeled according to an easy-to-understand scheme. The written documentation should provide a key to the cabling labels.
Switches are the heart of a SAN. Each switch should have its configuration and other information documented. The zoning and LUN information should also be clearly laid out. The documentation should include copies of any scripts you use, especially if you created them.
Include a change log in the documentation file, listing any and all changes to the hardware, firmware and configuration.
Brocade also suggests preparing an edited subset of your documentation to your technical support vendor to help in troubleshooting. This material should not contain sensitive information like sever names and customer information, but it should include your SAN topology, operating system information, patch level, storage types and firmware and driver versions. Giving the technical support vendor this information up front can save a lot of time-wasting questions when you call for support.
For more information:
Advice: How do I document my SAN?
Advice: More on SAN documentation
Rick Cook has been writing about mass storage since the days when the term meant an 80 K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.
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