Microsoft Visio is one of the most popular network diagramming packages available, and with good reason. It has superb capabilities, albeit with a bit of a learning curve. And since it is widely used, sharing diagrams with colleagues and other IT professionals is easy. I've used Visio to diagram everything from a basic server farm to a fiber network diagram for a 60-building college campus network that directly traced every single strand of fiber-optic cable from its origin to its final destination.
In this article, I will address the issue of documenting a large server farm. Specifically, I will show you how to set up a big-picture diagram that provides an at-a-glance look at a server farm with hundreds of servers. I've also created a sample Visio file that employs the techniques I'll present here.
Why do it?
Using Visio to diagram a server farm goes a long way toward enabling you to more effectively manage, maintain, and upgrade that environment. In addition, keeping proper documentation, including diagrams, makes life much easier for those who assume your role if you leave the organization.
Server farms are becoming more and more common and run in a variety of environments. They may exist in racks, in cabinets, on shelves, or in any number of places, and they can also exist on multiple networks, such as a private and a public network and/or a front end and a back end.
Over the years that I've been managing and documenting servers, I've gotten some excellent tips from mentors, and I've developed a system for diagramming and documenting server farms that is easy to maintain and provides a quick view of the infrastructure.
I don’t consider documentation to be just a picture of what the server room looks like, with information about each system. Instead, I view documentation as an overall representation of an environment, with information that matches the infrastructure, right down to the color of the patch cables being used. I can walk into my environment with this documentation and immediately identify the various portions, including determining which network adapter is on which network. I find great value in the logical, overall diagram of an infrastructure, especially when it comes time to make a change to it. It’s much easier to brainstorm ideas on how to make a change if you have an overall picture of the environment.
Where possible, I also create separate documentation to keep track of individual racks and provide a more granular view of the servers. For more detailed information on documenting specific servers, check out "Use Visio to diagram your rack server equipment."
If a particular service or product has a particularly complicated structure, I may also add a page with details on exactly how it is laid out. That way, it can be easily understood by others who may need to work with it.
What I keep track of
When I'm creating a high-level document of my infrastructure, I like to include this key information:
- Network connections (public or private?) to the machines, and addressing if space permits
- The server’s operating system and version
- The server’s manufacturer and model
- All incoming connections to the network
- Specific routes to and from the machine, if possible
- The specific role of the machine (DNS, DHCP, Web server, database server, etc.), where applicable
You'll notice that in the sample Visio diagram, I didn't include rack number and rack position due to space constraints. However, if you have room in your diagram, you could include this type of information.
My first diagramming standard is a basic one: I like to be able to read everything that is on the documentation page. I know that this sounds simple, but if documentation is not clear and easy to follow, it will be much less useful. Therefore, I like to make sure that the page orientation and text size make the document easy to follow, read, and understand.
In addition, in my big-picture diagram, I do not use vendor-specific symbols or even the generic ones that are supplied with Visio. Instead, I use simple boxes and lines. While the colors may vary, depending on the equipment, I like everything to be uniform.
My preferred layout also allows for multiple networks to be logically shown on the same page of the diagram. For example, suppose your company has two separate public networks and three private networks, all of which are interconnected. With the documentation design I use, all of these networks can be shown and are laid out in a logical manner. I generally pick a unique color for each network, but I try to keep related networks of similar colors. For example, my public networks are connected with lines that are shades of green, while my private networks are connected with lines that are red, pink, purple, etc. I then try to match the patch cables to this color scheme (or vice versa) to make troubleshooting and maintenance easier.
Using my Visio template
My downloadable Visio file consists of two diagrams. The first diagram (the first tab) is a blank template that you can customize to meet your needs. The second diagram (the second tab) is an example diagram with a tutorial. It's filled out with sample information and includes some helpful information on how to use the template.
Remember that my approach for this overview documentation is somewhat minimalist, and I don't include every detail about the installation. I leave the details for separate documentation views that drill down into the hardware, the OS, and other variables. You may be surprised at how sparse the blank template looks without actual pictorial representations of the equipment, but the data is more prominent and it’s easier to read once you fill in the data.
If there's one word that describes my template, it's simplicity—and that is by design. For an overall documentation strategy, I recommend keeping a documentation binder with the big-picture documentation at the front and the supporting, detailed documentation on separate tabs behind it.