Related link: http://techrepublic.com.com/2300-10879_11-5896894-1.html
Whoever redid the cabling in this server room should attach a copy of the final slide to their resume. If I was hiring a server room engineer, I’d only have to take one look at the photo and I’d immediately offer him the job.
Cabling is an artform. You need good tools, supplies, patience, and above all, discipline. You can’t just wire up a new server room and leave it at that. Because sooner or later the quality starts to fade. Somebody will use the wrong color cable, or they’ll run a patch in between cabinets for a temporary job. Then in a year, what started out as a nice setup has turned into an unmanagable mess.
It looks like the guy who took on this project had the luxury of being able to take every server down at once and just rewire from scratch. Not too many people can do that, which is understandable. Once a server is in production, it’s hard to take it down unless you have long maintenance windows. And fixing the wiring of racked servers on a 1 by 1 basis is not a simple task.
The great thing is, I agree with every point that camarodave made when he described the work he did. The following is a reinteration of some of his ideas, with my own personal experience mixed in.
Get rid of the cable management arms
The management arm of a Dell 2650 adds seven inches to the overall length of your server, and all that ends up doing is blocking airflow.
But, you may ask, what if I need to fully extend a running server?
The only reason you should ever pull out a server from the cabinet is if you’re doing maintenance. And if you’re doing maintenance, then there’s no need for the server to be cabled. It’s my experience that when a cabinet is fully stacked with servers, cable management arms actually make it more difficult to pull out equipment.
Keep a well assorted stock of cable lengths and colors
At my first job, I had about 10 different category five cable colors that were assigned by Ethernet, Serial, T1, digital phone, POTS line, etc, etc. At my second job, the standard was only two colors: Ethernet and OOB Management (serial or KVM).
Unless you’re very good with a crimper, buy a large stock of cables in multiple lengths. If you can handle the cost, break them up in 1ft increments (3ft, 4ft, 5ft, etc). After you wire 2 or 3 identical cabinets, you’ll get an idea of what your inventory stock should look like.
It’s unlikely that you’ll ever need cables shorter than 3 feet. Keep in mind, you’ll always need up to 19 inches in length to go horizontally across the patch panel; maybe more depending on where the network ports are located on the server.
Design your perfect cabinet (or rack) and establish a standard
Build out the perfect rack or cabinet. Make sure you have enough power outlets running down the sides, and create a standard layout for patch panels and cable management panels. The goal is to make sure you can accomodate the power, network, and cooling needs so you can put the most computing power into your enclosure.
A common problem with some cabinets is that one resource suddenly becomes overutilized or unavailable. For example, all of the outlets in a power strip may be fully populated, but the cabinet is only half full. To correct this, power connections are migrated to a strip in a different cabinet, or strips might be chained together.
The goal is to make every enclosure configuration identical. If you can afford it, throw in more power outlets and network ports than you will initially need; you’ll save more money in the long run. Since server hardware is getting more powerful in smaller form factors, you could find yourself trading in all of those 3.5 inch servers for 1.75 inch servers. You’re saving space, but your power and network requirements end up doubling.