Cable Management Done Right

by Chris Josephes

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.



13 Comments

roger69
2006-03-01 10:46:14
Good pre-made cable source
What do you or others recommend as good sources for cables in one-foot increments?


I've found a few places online, but does anyone have experience with specific vendors?

cpj
2006-03-01 19:31:45
Good pre-made cable source
I found that Cat 5/6 cabling prices can fluctuate depending on order size or vendor relations. In one case, I had a discounted price because the company providing the cables also worked on a premise wiring contract.


In another case, I found a really good price on cables, only to find that when they were shipped, the lengths were not labeled on them. I also wasted a lot of time cutting away those useless rubber boots on the ends.


Here are a couple of reference links for special cables/cords that I occasionally need.


Belkin right-angled power cord
http://catalog.belkin.com/IWCatProductPage.process?Product_Id=16248


Three foot power cord
http://www.cablestogo.com/product.asp?cat%5Fid=1015&sku=03129

ikoenig
2006-03-12 15:12:53
Cable management done right? if you don't care about several things
This looks great but obviously this doesn't work for many places. My data center has several reasons why this won't work and the cable management arms aren't just a "nice to have" but a requirement. Also it is obvious that his data center doesn't have 99.99% uptime needs. It easily took several hours to complete the rewiring he was doing. For my data center to do something like that it would need to be done individually servery by server in a well scripted and organized manner.


Servers get pulled out not just for maintenance.


In some situations a server has crashed and will be rebooted in a couple of minutes, but has its error lights on. An operations person can check the error lights (which are in the top of the server for the details.. ie HP orange or red lights) and then hit the power button to return it to service. By powering the system off you've lost that very critical diagnostics information.



Servers get pulled out for maintenance but do not get powered down.


Some of our servers are running hot swap memory boards for close to if not 100% uptime. As such when a hardware failure event occurs that server needs to be pulled out of the rack to swap out RAM or a Memory Board or power supply or other hot swappable item. Slowly we are phasing these out for redudant servers instead of single points of failure, but that won't be complete for close to a year at best.


That Cable Management is just like a demo house. It looks great, has pretty colors and appears to be perfect, but reality has a way of adjusting that.


The statements for standards are exactly what we have. It gets us just as far if not farther than getting rid of cable management arms, which are a hindrance but necessary evil.

THENetworkDesigner
2006-03-18 16:12:28
We made cable management hard
For 30 years we've been trying to expire excess patch cable in a duct system that was designed for routing, not storage. The results are always disastrous, until now. It took a fed up contractor to build storage between the rack rails and relocate rear management where it belongs, behind the patch panel. Since the rack is 19" wide, the math says that a 2ft cable will always supply the connection and leave just enough slack to form a single coil and store that coil between the rack rails in a storage compartment designed to help IT managers neatly organize their patching environment and save $2000 per rack over the failed offerings of the last 30 years. This solution comes in a kit that contains 24 or 48 Fluke Certified 2ft CAT6 patch cables and a real cable manager. If you haven't been to http://www.neatpatch.com , then you don't know just how simple building a network can be when you properly use the real estate between the rack rails of every data rack and cabinet. There are currently 22 distributors worldwide selling this wonderful cure for the worldwide epidemic of entangled patch cable environments. While this site is not fancy, it is fully pictoral and each photo blows up to full screen, so that you can see in full detail just how simple and real this solution is. Who'd have thought that a cure this good could svae you so much money.
wsanders
2006-05-31 15:59:18
Cabling Neatness inversely proportional to Ability
That's my experience! Only PHBs make system administrators classify links by color and bundle them up into neat little fascia. Last PHB that made me do that, his only other accomplishment was ordering a bunch of Frankin-Covey posters for the server room so other PHBs could bask in his glow. What a dumbass!


Cables want to be free! I can trace all my cables from host to switch in a minute or two when I need to, but, then, since I'm never pinching cables by putting nylon ties on them, or accidentally nicking them when I cut the ties off, I never have physical network problems. I also have the luxury of individual patch panels on each rack, and a rack-to-rack master panel, and I do draw the line at stretching cables between cabinets. If you place a cable where a door cam be slammed on it - excommunication!


Now, about those cable management arms; like Seinfeld says, what's up with those? Do they go anywhere except into our landfills?


-wsanders
http://wsanders.net

THENetworkDesigner
2006-08-01 09:25:31
BICSI(www.bicsi.org)is the world's foremost educational source for telecommunication cabling. On June 10th, 2006 they too sought out a better solution for cable management, and of all the companies throughout the world at their disposal, they chose Neat-Patch. Neat-Patch didn't let them down. What was the typical nightmare (http://www.neatpatch.com/BICSI/Makeover/Before.JPG) became the dream network that all IT managers dream of (http://www.neatpatch.com/BICSI/Makeover/After.JPG). The Neat-Patch solution is mathematically proven to be reliable in any situation. If you break a LAN equipment rack down to its lowest common denominator, you end up with the number 48, which is the maximum number of ports you can have in 1 rack space unit. This is a 1U 48 port ethernet switch. If you place a 1U 48 port switch below a 48 port patch panel with an NP2K648 in between, adversarially the obvious question is "what if I'm not using all my patch panel ports?". No problem. If you've cabled for the future and you are at least 50% efficient with your patch panel terminations, you'll occupy the rest of the switch with your next patch panel which will be below a 1U blank panel and your next NP2K648. Why the blank panel? If you've cabled for the future, then you must allow room for the future. When port 49 is needed, simply replace the 1U blank with your next switch. In retrospect, we have positioned receiving stations and digital sources in equal, yet overlapping ratios that cannot fail and will never require the use of anything longer than the 2ft Fluke Certified single coil circuits that are provided with the NP2K648. We found that using this arrangement, we could neatly organize 384 workstations in a 7ft rack including a 1U fiber drawer and a 4U rackmount UPS for a retail price of $1600.00. We priced the market leader's (Panduit)using 2 WMPVS45's, 8 WMP1E's, and 384 UTPSP10 CAT6 patch cables for a total price of $4,470.30 (Graybar Quote# 203354414)and the results were the same mess we've been battling since the dawn of rack mounted interconnect systems. While this is an example of a large application, the Neat-Patch system is very versatile and their downloadable cabling guide contains many different layouts based on different switch styles. If you're attempting a retrofit and don't quite know where to begin, Neat-Patch will draw up your network for you using CAD converted to PDF and send it to you within 48 hours free of charge. So, if you have an extra $3,000 lying around and want the traditional mess, that's your business. If you want a neat, organized network while saving over half of your cable management budget, you need Neat-Patch.
Yike
2006-10-16 20:13:52
"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."


Your experience sounds pretty limited. They make hot-swap PCI slots and memory slots for a reason. Some people use them. When cabinets are fully stacked with servers or even 25-30% stacked with servers, cable management arms ARE A MUST if you need to work on a live server. Your statement is only true if you want to power down and take a server out of commission every time you need to open it up. A very short sighted and simplistic statement by you to think that you experience is typical. Go into any real high-end production environment and you are not shutting down a server whenever you like. That is the whole point to hot-swap components.

Yike
2006-10-16 20:19:51
"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."


Your experience sounds pretty limited. They make hot-swap PCI slots and memory slots for a reason. Some people use them. When cabinets are fully stacked with servers or even 25-30% stacked with servers, cable management arms ARE A MUST if you need to work on a live server. Your statement is only true if you want to power down and take a server out of commission every time you need to open it up. A very short sighted and simplistic statement by you to think that you experience is typical. Go into any real high-end production environment and you are not shutting down a server whenever you like. That is the whole point to hot-swap components.

Patch Cables
2006-12-29 12:47:28
Oh wow! That is a thing of beauty. Beforehand it looked like willow tree.
cps
2007-02-28 03:37:15
Guys, I couldn't agree more. NeatPatch is an engineering masterpiece. Recently acquired some units through their UK distributors ( contact them at www.neatpatch.co.uk ) to use in an overhaul of a comms room - It was so simple to work with and the results were outstanding. An infinite improvement on the spaghetti-technique used to 'manage' the cables before we got there!
Several hundred out of 10 and a slap on the back for the guys who invented NeatPatch.
John
2007-03-07 14:36:17
Thank you for the advice. I'm working on rewiring a data center myself and this has helped spark some new ideas on how I should approach the task.
PolishPaul
2007-03-22 19:16:13
http://www.deepsurplus.com
Justin Campbell
2007-12-07 11:55:23
But NeatPatch doesn't really do much for modular switches. I'll stick with verticle cable management, it looks pretty, and I never have any problems tracing cables and such. You could do better than NeatPatch if you just put a 48-port patch panel adjacent to a 48-port switch and run 6-inch cables.