One thing that always irritated me as an end-user is that none of the vendors had any real answers for cable and label management, at least not anything that didn't require a professional services engagement. In the end I had to develop my own solution based on what worked for my company and the data centers where I worked. Someone once told me, “Anything worth doing is worth doing well.” This holds just as true for the cabling aspect of any data center.
Over the last few years, I have worked in many data centers of all shapes and sizes, and I’ve noticed is people tend to focus on the state of the equipment servers and storage more than the physical layers of the facility itself. But those layers, in my mind, are more important than any of the servers or storage. For example, if you build a house and use cheap cement but buy really expensive furniture, and the house falls in, your project plan contained a huge error. I realize this may be a tad overstated, but I just want to convey the need to have an efficient, well managed data center.
Ideally, cable management should start with planning for a new data center, which provides a clean slate. There are a handful of categories for cable management which include:
- Server Cables (Copper, Glass, Power),
- Storage Cables (Copper, Glass, Power),
- Network Layer (Copper, Glass, Power).
The first thing you need to think about is how these cables should be dressed and/or tied down:
- Selecting which cables to be run overhead versus under the floor (the power and network cabling should be separated from one another if possible).
- Use of structured copper and glass cabling plants to punch-down panels, fibre tubs, raceways, conduit, and retractable trays for splice management.
- Use of patch panels in the server or storage racks with structured cabling running back to the main network line-up.
- Use of cable management trays for the network devices.
- Use of cable management side panels to cover extra cable slack and tie offs.
- Location of rainfalls for the mass cable drop-in’s into the network row.
Planning this requires making a lot of decisions to create an efficient data center cable plant. However, there are many places to go for design assistance, I am just pointing out some of the areas you will want to consider.
The next stage is placing your servers, storage and network gear into the data-center. There are some things to keep in mind here as well. With servers, the first thing NOT to do is throw away the swing arm. Use it as intended, for cables. If the storage comes pre-racked, the cables should already be dressed. Ensure that those are placed to provide free access and visibility so you can see where each one goes. On the network side, which will probably be one of the most cumbersome areas for proper cable management, ensure that ample cable trays/rainfalls are provided for the significant number of cables that will come into this area.
A new data center, however, is a rare opportunity. The more common situation is happens when you inherit and exiting facility. What opportunities for improvement you have will depend on how bad the cable plant design and implementation was from the beginning. Basically, you have two choices:
- Total Replacement: This involves planning a new cabling infrastructure, shutting the facility down, ripping down the old, and swapping in the new.
- Partial Replacement or Re-Use – This requires disconnecting the existing cable and moving the existing cabling into new trays, rainfalls, server cable arms, etc., and then reconnecting.
An important question to answer with either of these processes is whether the entire facility needs to be done at once. Often the better option is to do the new implementation section by section, over time, working with one or a group of racks at a time to minimize the number and impact of planned outages
This process is calculated to make the data center manager more popular with users, but when you have a mess to clean-up, there are always going to be some sacrifices. I have had real success planning these clean-up sessions around data-center outages, which most corporations have from time to time for patching or power upgrades.
The biggest drivers behind designing, implementing, and maintaining proper cable management from the beginning, are the ability to provide adequate cooling to the devices (versus trying to push the air through a huge mess of cables) and minimizing the pain of trouble-shooting problems involving the physical layer. Speaking from experience, trying to solve some issue at 1:00 a.m. is much less frustrating when you can quickly and easily identify the cable infrastructure instead of crawling around or under the raised floor trying to determine what is connected to what. A good cable plant will also minimize the danger of inadvertently pulling out the wrong cable and causing a drop in application or network service. If you were crawling under the floor into a spaghetti mess, there is always the possibility you may catch your foot, hand, screwdriver or whatever, on a power/network cable and cause a real outage.
If this is something you haven’t had much time or staff to focus on, I encourage you to do so, as it will ensure longer life of your equipment and your data center cable plant and makes for a much happier system administrating staff as well, once the problems have been corrected.
One last point: getting to that utopian state in your data center does little good if processes and procedures aren’t put in place to ensure that the environment is not only maintained but documented as well.
Once you have crawled out of your cable plant nightmares and come out clean on the other side, you will have a cable plant and data center that you can be proud of. It’s definitely not a sexy project to undertake, but your sys-admins, operations staff, and engineers will thank you for the time and effort you spent designing or cleaning up your cabling environment. Because at the end of the day, properly strung glass of copper will ensure you have as an efficient an environment as possible.