Server "closet" design

[InlineFive]

Hi everyone,

A small business I work for is going to be migrating to a new building in the next two-three years. Along with this comes a lot of technology changes but with the help of some friends who have experience in the field I am sure that will go smoothly.

My real question comes down to the server "closet". Nothing I have learned in college or elsewhere has covered anything like this and I am not sure where to start. We will only need one rack so the room only needs to be able to support one 40-45U rack at most. We won't have the rack filled immediantly but I want the room to be able to support the power and environmental requirements of a filled rack at higher loads. As well as accomodate the assorted phone equiptment, unless we migrate to VoIP off of the bat.

(Unless you think that for future proofing it would be good to have enough space for two racks. Technology keeps getting smaller so I thought that environment and power are more important factors.)

The room should be accessible enough to make future wiring fairly easy without sacrificing the ability to contain a sustained environment. Once again, I'm going to get a consultants input but I'm planning on wiring the backbone of the building with Cat7. Although I am finding conflicting views as to the backward compatibility of Cat7 cables and jacks to standard RJ45 equiptment. As of yet I'm not sure if it makes sense to lay fiber if we can move to 10Gbps in the future.

I plan to wire all of the client's jacks with Cat6, as the cost difference between Cat6 and Cat5e isn't huge. How many jacks do you think should be in a room?

Do you have any suggestions on a good place to start research for this?

Thanks in advance for your time and experience.

Aidan

 

[spidey07]

follow eia/tia standards to a T and you'll be just fine.

Put this in the statement of work, must follow EIA/TIA standards. I can't ramble off the exact numbers but pathways/spaces, grounding, cooling come to mind.

And your backbone should be 50 micron MM high bandwidth fiber.

 

[cmetz]

InlineFive, first of all, have a chat with whoever is doing the facilities stuff for this move and make sure that they have you in the loop with the architect for the interior build-out. If they hire a reasonably competent firm and you aren't out in the sticks, it's 2006, competent architects have done this sort of thing before and can be very helpful.

Now, that said, always build the room bigger than you expect. For one thing, you need really good clearance around all sides of the cabinets. Oh, yeah. Cabling goes to 19" racks. Machines go into four-post 19" cabinets, on rails. Big difference between a rack and a cabinet, space wise.

Make sure you have plenty of power and supplemental cooling. Cooling needs to be able to handle a couple of cabinets full of gear (do the math, Watts -> BTUs, I forget the conversion), but also needs to have a min load that's pretty low. Watch that min load on cooling - it's a big gotcha - or your cooling will short-cycle and die over the weekend and your gear will fry. And make absolutely sure that the cooling stays on 24x7, which means its your own unit and not the building's. Pull in at least two 120V 20A circuits, four would be better. You'll want to buy UPSs sized appropriately too.

Oh, and buy a Sensaphone. Google.

Cabling wise, I'd put in cat6 drops and 10G-rated fiber (not just any will do!) to any other wiring closets or places you think might someday turn into an extra switch/server spot. I am not yet convinced that cat7 is worth it. I am convinced that 10G-rated fiber will do 10Gb/s, which will serve you well for quite a while. If you really are worried about outgrowing 10Gb/s, run a bundle of multiple fibers so you can link aggregate later.

Jacks in a room depend totally on the kind of company you are. No matter what kind of company you are, you should at least have two cat6 jacks per seat - one for a computer and one for an IP phone (if you use RJ11 phones, make some adapter cables and use that cabling infrastructure later - you'll probably end up on VoIP later the way the market's moving). If you want printers near people, add a third. If you're a tech company, add a few more, as many as your management will let you get away with - I've never ever seen a tech company where they have "enough" ports. If management complains about the cost, explain to them the man-time it will cost to debug when some idiot plugs a $10 SOHO switch into drop ports. It's that much more manageable when you can home-run everything.

Anderson makes some inexpensive vinyl industrial anti-static tiles. They're cheap, easy to install, easy to clean, and anti-static. Highly recommended. Raised floor would be more fun, but they're expensive. Overhead hanging trays are cheaper and get the job done.

Anyway, those are some random thoughts that should help.

 

[cmetz]

spidey07, didn't you just have a little rant about how MMF is dead and everyone should always use SMF?

 

[spidey07]

Originally posted by: cmetz
spidey07, didn't you just have a little rant about how MMF is dead and everyone should always use SMF?

meh, I run both on all new buildings.

 

[InlineFive]

Nevermind, it looks like SMF is for long distance runs which we certaintly won't have. If you think that MMF is going to have enough support in the future to migrate to 10Gbps then I'm going to wire with it because of lower costs.

Oh, and thanks for the help to both of you. Extremely beneficial and it gives me a place to start.

 

[cmetz]

InlineFive, I would use SMF exclusively anyway because SMF and MMF mix poorly. I've had one too many cases of bozos buying blue or grey fiber patch cables and then plugging them into various places in the cable plant... and when you connect a MMF jumper to a SMF run or vice versa, it usually doesn't work. That "usually" part is key. Kinda like how various Ethernet no-nos usually don't work. And when things worked for a while and then stop working, and you can't figure out how it ever worked... anyway, it's just much more idiot proof if your facility is all SMF or all MMF. One less thing for the monkeys to screw up.

 

[spidey07]

Originally posted by: InlineFive
Nevermind, it looks like SMF is for long distance runs which we certaintly won't have. If you think that MMF is going to have enough support in the future to migrate to 10Gbps then I'm going to wire with it because of lower costs.

Oh, and thanks for the help to both of you. Extremely beneficial and it gives me a place to start.

If you are thinking about 10G then the decision is already made for you. You WILL be running single mode.

Personally I'd still run some high bandwidth MM just because overall the cost of the fiber is cheap, it's the optics that kill you and if you can get away with doing 10G over MM at least you have the cable already there.

cmetz is right though - you had better have people that know what they are doing if there is a mix. Good documentation of the cabling plant will go a long way.

 

[InlineFive]

Thanks for the additional information guys. I was thinking about MMF because I have found 10Gbps MMF around and most SFP modules seem to use MMF.

But since you think that SMF is such a good idea (albiet more expensive) I'll definitely bring in a consultant with experience in dealing with fiber.

 

[spidey07]

Originally posted by: InlineFive
Thanks for the additional information guys. I was thinking about MMF because I have found 10Gbps MMF around and most SFP modules seem to use MMF.

But since you think that SMF is such a good idea (albiet more expensive) I'll definitely bring in a consultant with experience in dealing with fiber.

inlinefive,

I definately suggest a consultant. Only because I don't think you've been exposed to this sort of thing. I'd be willing to do some of the design/RFP/SOW work for a fee.