New Data Center Standard 196
mstansberry writes to tell us that the Telecommunications Industry Association (the people who brought you the CAT standards for unshielded twisted pair cabling) recently published a 148 page document meant to standardize the design considerations for every single aspect of a data center. The standard covers everything from site selection to rack mounting methods.
twisting (Score:5, Interesting)
CAT5 just seems to be twisted a little tighter, but CAT6 actually modifies the twist gradually, in a cycle that repeats every few feet, with each pair 90 degrees "out of phase" from the next. Plus theres (sometimes) a plastic "spine" in there to maintain spacing and/or bend radius. It's not obvious to me how varying the twists-per-foot along the cable should help - anyone know?
Re:twisting (Score:5, Informative)
(FYI, crosstalk is interference from a parralell channel in the wire)
Right answer, wrong question (Score:2)
Re:Right answer, wrong question (Score:2, Insightful)
Re:twisting (Score:4, Informative)
Re:twisting (Score:2, Informative)
There is one caveat though and that is only the orthogonal components (to the wire) of the magnetic field induce a current and so by twisting the wires you minimize the orthogonal components.
At least that what
Re:twisting (Score:2)
Does common mode rejection still play a part in modern ethernet or othe
Re:twisting (Score:2)
Re:twisting (Score:2)
There are two ways to remove the common mode signal from a differential pair:
1) an opAmp
2) a balun transformer.
The reason why manufacturers use number 1 is because it is cheaper, tunable, and weighs less.
-nB
Re:twisting (Score:2)
Cat 3 - 10 Mbps
Cat 5 - 100 Mbps
Cat 5e - 1,000 Mbps (1 Gbps)
Cat 6 - 10,000 (10 Gbps)
Re:twisting (Score:5, Informative)
Varying the twist rate along the run of a pair, as well as doing what you can to keep it out of phase with other pairs by braiding, or other means would make it possible to set up a longer cable run without viable phase transfer points that could cause signal bleed between pairs.
However that's just conjecture on my part. I am sure someone will come along who can give us the math to show that my conjecture is entirely wrong.
-Rusty
Re:twisting (Score:2)
tightly twisted pairs take longer to go through than loosely twisted pairs, and so instead of 2 parallel antennae inducting into each other you have two an
Re:twisting (Score:3, Interesting)
basically for 1gbps its just starting, past 5gbps (10g copper spec calls for this though a working group is trying to run 10g on cat5 (boggle)) you need this kind of thing, and it happens to cut down on rf interference and reception, another handy thing, c
Re:twisting (Score:4, Informative)
In other words it reduces cross-talk between cables
Re:twisting (Score:5, Informative)
Re:twisting (Score:2)
http://whatis.techtarget.com/definition/0,,sid9_g
Re:twisting (Score:2)
http://discountcablesusa.com/ethernet-cables.html [discountcablesusa.com]
Re:twisting (Score:2)
A good article on cat 6 can be found at The Data Center Journal [datacenterjournal.com] It points out things like why you don't want to use anything that would clamp down to tightly on the Cat 6 runs, like nylon tie-wraps. Use velcro instead. That said, I've run 1Gbps through home-made Cat5 with no errors, albiet for short distances (less than 50 feet).
Still, $250 just to read a standar
MECC (OT) (Score:2)
MECC? Did you get your nick from the old Minnesota Educational Computer Consortium?
Curious
Seraphim
Re:twisting (Score:3, Informative)
Re:twisting (Score:2)
Re:twisting (Score:2)
As it happens, the varying twist rate helps prevent cross-talk, reduces the effect of the cable acting as an antenna, and generally looks fairly cool. The dialectric of the insulation doesn't really feature, unless you're talking about shielded stuff.
Re:twisting (Score:2, Interesting)
Re:twisting (Score:3, Informative)
When all of the impeadances match, the power or energy (can't remember which, and
Re:twisting (Score:2)
Not this again ... (Score:3, Funny)
How about letting a bit of originality in once in a while?
Oh yeah
---
jon_edwards@spanners4us.com
Re:Not this again ... (Score:2, Insightful)
When designing a Data Centre, I really don't think the number one priority is to make it an artistic statement or a fun place for the IT staff to hang out in.
Re:Not this again ... (Score:2, Insightful)
Originality and creativity have certain places in the world. Just because you have guidelines and standards doesn't mean you can't be creative. Programming languages have standards, that doesn't mean programmers can't create original programs. If there were no coding conventions and standards, you'd almost never be able to examine someone elses code. "Wait a second, why are all the integer variables stored as strings? And I think
Re:Not this again ... (Score:5, Insightful)
Out of the costs involved in setting up a data centre, $250 wouldn't even qualify as a rounding error.
Doomed to failure? (Score:5, Insightful)
When you specify something like a cable, it's straightfoward to get it right, because the job the cable does and the way it's used is very well understood and doesn't vary between users.
With something complex like a data center, there's so much variance in how they're operated, exactly what they do, where they are, etc...having a standard may well *not* fit everyone's needs, either because their needs were not perceived or understood at the time or because their needs simply cannot be met by the standard.
--
Toby
Re:Doomed to failure? (Score:5, Insightful)
True.
But when you have a formal standard, you have something to measure against. Every aspect of the data center design is not only standardized, but the how's, why's and therefore's are spelled out. If you suspect the standard doesn't meet your needs in some respect (a clear lack of surround sound for late-night fps tournaments, say), it makes it clear exactly how your criteria changes the requirements, and it makes it much easier to see how it could impact the rest of the design.
So even if you use not one single recommendation (we need the disco ball, damnit!), you have something reasonable and well documented to compare against, which makes your job easier.
AMEN (Score:3, Insightful)
Purpose of the Datacenter (Score:4, Informative)
But not all datacenters are equal for a reason. I've seen maybe 20-30 datacenters in the past few years for various clients and they all have different features, different offerings, and different goals.
I'll list a few of the big differences I've seen in my experiences:
Some want to be in the downtown core, close to many businesses, but charging a premium for the space. Others claim that being in the outskirts of the city provide security in the event of any problems (mainly hyped due to 'terrorist attacks').
Some feel the need for N+2 generators, others more. Some feel that a fallback to city power if their PDUs ever fail is good, and others feel there should be a whole other protected power distribution system (at an extremely high cost for something rarely used).
Some like cooling each rack from the top, others blow it up every other isle and suck air down on the opposite. Some cool the whole room, claiming lots and lots of cooling units around the outside does the trick.
Some like the datacenter two stories underground. Others claim that they're a first target for flooding and other problems stereotypically associated with a basement. Others say that the datacenter on the 10th floor of a tower is inaccessable and subject to other security feats of the building.
Some like dedicated buildings, others like quietly slotting themselves in office towers.
A few I went to were monitored from 3000+km's away, and others had 24/7 onsite staff. Some had technical electronic keys, and others a simple mailbox key. Some had biometrics, others just a key.
One I went to even had outter walls capable of withstanding most missiles. Others had windows with only paper over them for security reasons.
Some let you roam freely by a security personelle and simply log equipment, others weigh you on the way out to make sure that you didn't take anything you didn't show up with without signing it out.
The point is each of these serves a very different purpose. If you are going to have lots of untrusted people working on equipment, it's important to make sure nobody takes anything. Each one has its advantage and disadvantage, and I don't think any one of them is 'right'- it's just trying to find a solution to problems that experience has provided.
Is there a right answer with anything? Who is to say that any answer is right or wrong? They're just different solutions to the problem. If power stays up, systems are secure, systems get cooled, and the network is available, who is to say the solution is wrong?
-M
Re:Doomed to failure? (Score:2)
Until it comes time to justify to the PHBs and bean-counters why you didn't follow every recommendation in the standard, to the letter. Sure, YOU know that your custom solution is more appropriate than the baseline, but how are you going to defend it to people that don't understand it as well?
Doomed! Curical missing pieces (Score:2)
1) How to determine caffeine / worker ratios, where to put the coffee pot and soda machines, whether and how much to charge, and a list o vendors who still deliver Jolt.
2) Air lock standards so you can crank up a stereo in the machine room loud enough to drown out the machine noise, without irritating fellow workers in cubes, managers walking around, and customers waiting in the lobby with different musical preferences.
3) Minimal
Re:Doomed to failure? (Score:2)
When AT&T built its long-distance microwave network, every center was the same as well. If you're running a nationwide network of branch data centers, you need standardization.
Pity it's $250 for a peek (Score:5, Interesting)
Just not curious enough to pay the price to find out
Steal the F*ing Manual (Score:5, Funny)
Seriously. If all manuals were that expensive there would have been no 'RTFM'. It would have been 'STFM'.
Re:Pirate the F*ing Manual (Score:2)
But of course (Score:2)
Re:But of course (Score:2)
Re:But of course (Score:3, Interesting)
Well that sure is an interesting comment. Just how many marks do you think that you can round up who would each pay $250 a pop for a 148 page report because it "is bound to have some good ideas in it"? At that price it wouldn't take too many people to convince me to crank out 150 pages of opnion, particular when the subject is as broad as "every
Re:But of course (Score:2)
Re:But of course (Score:4, Funny)
You just described our setup almost exactly.
Re:But of course (Score:2)
(I think sometimes all these datacentre folks forget that there are a lot more small businesses out there than the handful of transnationals that can afford thousand machine datacentres.)
The best-organized datacenters I've seen... (Score:2)
Re:The best-organized datacenters I've seen... (Score:2)
The cleanest data center I've seen did this, ran the power under the floor, and ran all the data through overhead cable trays.
/. effect (Score:2, Insightful)
Cheap datacentres (Score:4, Funny)
Link to the document (Score:2)
Re:Link to the document (Score:3, Insightful)
Slashdot moral concept #7: If item is perceived to suck, stealing - oops sorry, forgot Slashdot moral concept #6 - infringing it is allowed.
Example: "If $band would put out better songs, maybe I'd buy their album. Until then, I will continue to use BitTorrent to get their material."
Re:Link to the document (Score:2)
Or everything you can eat before checkout in a supermarket is free, however in a restaurant the rules are different again.
Re:Link to the document (Score:2)
Corporate welfare at its finest.
Of course, these data center standards haven't reached that point, but who's to say they won't? It's being positioned that way. We'll see whether or not it ends up that way.
Re:Link to the document (Score:2)
Which won't be anytime soon, because "TIA is accredited by the American National Standards Institute (ANSI) to develop voluntary industry standards for a wide variety of telecommunications products." (from the TIA website [tiaonline.org]). They don't have the power to write laws.
Re:Link to the document (Score:3, Interesting)
Hi, your datacenter isn't TIA-compliant. We won't sell you xyz hardware. We won't sell you xyz fire-suppression system.
Hi, I notice your datacenter doesn't have a fire-suppression system. I have to close it, by law, until it's installed.
Hi, I can't install a fire-suppression system until you bring the datacenter up to TIA-standards.
Needless to say, TIA doesn't have to make their spec law for it to be able to screw your datacenter over.
Re:Link to the document (Score:2)
Yeah, like that's going to happen! A company refusing to make money by selling you stuff? No chance. Some company will always be happy to sell it to you. Heck, if you can show me that all companies will act in that way, then you've just pointed me in the direction of my niche market where I can make shedloads of money!
Re:Link to the document (Score:2)
PDF HAS BEEN LEAKED CONTENTS FOLLOW (Score:2, Funny)
great news for colocation customers (Score:3, Insightful)
If you've ever tried to find a place to host your server in the past, you've probably found that not only does the price wildly fluctuate between hosts for no apparent reason, but also it's very difficult to determine exactly what you're getting, even if you take the time and effort to actually visit the site.
I think that the disorganized fashion of colo services allows people to charge ridiculous prices
and get away with things that they wouldn't be able to do in a more stable competitive environment (like charging ridiculous amounts for bandwidth overage and support).
With some sort of standard in place, vendors will be forced to compete on more even ground, prices will be more reasonable, and users won't be afraid to leave their current colo provider because the next one could potentially be even worse.. Not that it will be perfect, of course - just somewhat better.
Re:great news for colocation customers (Score:2)
If you want the best price you have to know what that price is and ask for it. They'll sa
Re:great news for colocation customers (Score:2)
Re:great news for colocation customers (Score:2)
Re:great news for colocation customers (Score:2)
Alternatives to THIS book (Score:5, Interesting)
Interestingly enough, a quick google search for "data center design" comes up with more hits than one can shake a stick at, ranging from free to fairly inexpensive (under $100.00). I have to admit that I wonder if THIS magnum opus has anything in it that these OTHER resources do not cover.
It never ceases to amaze me at the number of books out there that are supposed to be useful learning tools that are nothing more than a slightly changed rehash of the man pages for a given program.
Regards
Dave Mundt
Re:Alternatives to THIS book (Score:2)
Sun also has some articles on disaster planning and such in the Data Center [sun.com] section of Sun Blueprints.
... and $250 is not a lot of money, when you're dealing with a buildout of millions of dollars, just for the data center (ie, not the actual s
Oh
Raised Floors? (Score:2, Interesting)
-AT
Re:Raised Floors? (Score:4, Informative)
Re:Raised Floors? (Score:2, Interesting)
At my colo, they run cold air from the HVAC under the raised floors and suck it up through the cabinets with a fans (and presure from the HVAC). They cool the cabinets, not the entire facility. It's odd being in a colo that is warm after freezing my ass off in previous facilities, but temperature monitering equipment of ours tells us that the closed cabinets stay quite cool.
Any Zinc Whisker failures? (Score:2)
Re:Raised Floors? (Score:3, Funny)
Re:Raised Floors? (Score:4, Funny)
I think I worked there.
Re:Raised Floors? (Score:2)
Re:Raised Floors? (Score:2)
The bigger the space, the more serious the data center. I did six months of consulting working in a data center that had a six foot raised floor, which wasn't enough to walk easily under because of the ducting and cable trays, but made moving around and finding stuff a lot easier. They had great filtrati
Re:Raised Floors? (Score:5, Funny)
Re:Raised Floors? (Score:3, Informative)
Re:Raised Floors? (Score:2)
I can't imagine what our server farm would look like if we didn't have a raised floor for routing cables, fibre, air, etc. Do you have any idea how much heat a rack of 1U servers can put off?
Re:Raised Floors? (Score:2)
Raised floors are passe (Score:2)
I actually was wondering if it might be good to use the raised floors as exhaust plenums. You could suck hot air near the ceiling in via raised stacks. The space was never good for
This is a really bad idea, sort of (Score:5, Insightful)
It can be a good idea if the techs get a hold of it though and stop giving my 2 inches of slack on these fiber runs and give be a proper service loop with good cable dressing instead of the rats nests I've had to fix recently.
Re:This is a really bad idea, sort of (Score:2)
I prefer a nice Italian for my cabling, but with the higher standards of CAT6 only the finest you can find is suitable, such as a very expensive red wine.
1 shoe does not fit all (Score:2, Interesting)
I wonder if they cover aspects like power phase balancing given alot of places have 3-phase and we all know how box's move about so the aspect of auditing the balancing across the 3 phases comes in. Why well power costs given you pay for the highest usage over the 3 and then there is the UPS aspects and resiliance aspects.
Oh and DR sites, if
April's fool? (Score:2)
I'd not take in too serious consideration this doc!
Why we need something like this (Score:2)
The Basics.... (Score:3, Funny)
Somewhere the US/Chinese government won't be monitor ing everything... still looking.
Sweet Zombie FSM! (Score:2)
Riiiigggghhhtttt....
Standard document (Score:2)
This standard isn't for the SMB or small colo facilities. This is more for the big corporate datacenters (my workplace is approx. 100,000 sq ft, and a 2000+ port SAN). These kind of places don't blink an eye at $250 for a book. Of course, in places like this, a vendor would most likely give a
Sooo, where is the torrent? (Score:2)
Perhaps its worth that, but i personally wont take a gamble that it is. Ill just keep doing things that work.
Would have been nice to read it.
Re:Hum? (Score:5, Funny)
Re:Hum? (Score:2)
Re:I hope it specifies floor monkeys have unix ski (Score:2)
This would be neat! Of course I doubt that the CAT would dare to take such a leap... I like your term reboot monkey, I think I'll use that... I usually refer to them as clickologists...
On another note, did any of y'all get a patch for your ciscos yesterday? It seems to be a pretty big one...
Re:I hope it specifies floor monkeys have unix ski (Score:2, Funny)
#1. Driving all the way to the data center at 4 am to find the keyboard plugged into the mouse port - "The keyboard's not responding", says the "engineer".
#2. Driving all the way at to the data center at 3am to see
Installed X and AIM after that and made the "engineers" read the commands off that provided they could get that working.
Re:I hope it specifies floor monkeys have unix ski (Score:2)
Yea, UNIX admins are better? (Score:2)
Ohh you can type fsck? Big fucking deal. You're not special. I love the command line and it's an awesome way get things done but it's also an awesome way for a dipshit admin to fuck everything up with little undocumented custom scripts and programs *everywhere
Re:Yea, UNIX admins are better? (Score:2)
Re:I hope it specifies floor monkeys have unix ski (Score:2)
Some people expect too much.
step 4 (Score:2)
Re:The three steps (Score:3, Funny)
Re:The three steps (Score:2)
That's common for standards organisations. You have to pay for things like Unicode and SGML as well (if you want to write a proper implementation and not just wing it, that is).
Re:racks/cabinets (Score:2)
Re:Expensive set of standards (Score:2)
The standard is used as common ground for reference and comparison. It doesn't just outline specs, but justifies them too. So they can look to this document to see how they may improve.
And as