So I finally had the chance to completely rewire my server rack at work...

Discussion in 'OT Technology' started by deusexaethera, May 16, 2008.

  1. deusexaethera

    deusexaethera OT Supporter

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    ...but the one thing I can't figure out how to do is route the feeder cables correctly. Right now I've got them hanging off an unused door hinge via a Velcro cable tie, and while that gets them up and out of the way, I know it's not the right way to do it, because...well, I can't put the rear door on as long as the cables are in the way.

    Up on top of the rack, about halfway along one of the sides, there is a removable grate; my guess is the feeders are supposed to go through there. Except, the grate could probably handle a bundle of 100 cables, and I only have three (two mains and a crosslink to a workstation switch on the back wall). Anybody got any suggestions on how I can do this up so it at least looks like it was done by someone who knew their shit?

    (pics would be great.)
     
  2. JayC71

    JayC71 Guest

    Lots of racks are different, so I'm not sure exactly what you're working with here. Can you post a pick for reference?
     
  3. deusexaethera

    deusexaethera OT Supporter

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    I'll take my camera into work in the morning.
     
  4. Mike99TA

    Mike99TA I don't have anything clever to put here right now

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    If your racks are anything like the slew of different racks we have here, then yes the little square plate on each corner of the ceiling of the rack can come off and the cables should go through there (if coming down through the ceiling).

    At one of our Datacenters we have all cables coming from ladders on the ceiling going down in through the top, at another datacenter all our cables are coming up through the raised floor and most racks have an open space on the bottom for cables to feed through.
     
  5. 5Gen_Prelude

    5Gen_Prelude There might not be an "I" in the word "Team", but

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    Ummm - go thru the grate? What's the problem?
     
  6. deusexaethera

    deusexaethera OT Supporter

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    Okay, here's what I have to work with.

    The rack:
    [​IMG]

    The cables:
    [​IMG]

    The removable grate:
    [​IMG]
     
    Last edited: May 16, 2008
  7. dissonance

    dissonance reset OT Supporter

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    [​IMG]

    It's removable for a reason, and its on top and out of sight. Do you see any other places that the cables are supposed to be fed through?
     
  8. Mike99TA

    Mike99TA I don't have anything clever to put here right now

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    Its hard to tell based on your picture where the grate is in relation to the corners of the rack. It looks like its on the side of the rack midway between the front and back - if so thats pretty crappy, but I would still run them through there.
     
  9. dissonance

    dissonance reset OT Supporter

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    It looks like at toward the back on the top there is a bar running across that could be used to hold the cables up so they aren't resting on the top piece of equipment.
     
  10. Mike99TA

    Mike99TA I don't have anything clever to put here right now

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    Eh...they shouldn't be resting on the equipment anyway. You should run the cables down through the grate, and then down the inside-side of the rack and then back up and over to the server. Do your racks have wire management on the sides? Even if not you should be able to run the cables inside the rack down the sides (with velcro) so they dont sit on top of anything.
     
  11. deusexaethera

    deusexaethera OT Supporter

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    Yes, the cables are already routed down the sides:
    [​IMG]

    I should be more specific about what I'm trying to figure out: is there a "correct" way to attach the uplink and crosslink cables to the hole that the removable grate covers up, and is there a "correct" way to get them from the top of the rack to wherever they need to go?
     
    Last edited: May 16, 2008
  12. Mike99TA

    Mike99TA I don't have anything clever to put here right now

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    Yes, you remove the grate and run the cables down through that (then you throw away/store the plate). Thats what I was saying earlier.
     
  13. deusexaethera

    deusexaethera OT Supporter

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    So there's no sort of officially-sanctioned way to hold the cables in place as they pass through that opening? Just whatever works?

    It doesn't matter, I suppose, but since my boss is on vacation and I actually have the chance to do this right, I want to do it as right as possible.
     
  14. Mike99TA

    Mike99TA I don't have anything clever to put here right now

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    Most places that have cables coming down through the top of a rack have a cable ladder above the rack...then the cables come down in one clump into the rack. We usually just use a strip of velcrow to keep them looking nice on their way down. If your cables are running along the top of the rack before they curve at a 90 degree angle down into the rack you'll just want to make sure they're not going to bend too much or get cut on the edge. Other than that, velcro in liberal amounts usually does the trick.
     
  15. Sexual Vanilla

    Sexual Vanilla New Member

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    You don't want me to post a picture of the rack at our office. :mamoru:
     
  16. deusexaethera

    deusexaethera OT Supporter

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    Yep, Velcro is great stuff. Here's what I came up with:
    [​IMG]

    I wish I had a piece of 90-degree conduit that I could use to cleanly feed the cables up and out of the hole in the top of the rack, but this is good enough. At least I've got all the body panels on the thing now, for the first time since I started working for this company.

    Thanks for the input guys.
     
  17. deusexaethera

    deusexaethera OT Supporter

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    Yes I do. Either it's impressive as hell, or it looks like shit, and if it looks like shit, I seriously doubt it looks shittier than what I started out with.

    The rack I've been working on the past week and a half (yes, it took me that long to clean it up) was originally one of two, and there used to be...not a rat's nest, but a fucking handwoven Persian rug of cables connecting them, and the uplinks that ran to the back wall were just sort of draped from high-point to high-point until they got where they needed to go. I literally had to pick my feet up like I was walking through underbrush when I went in the room, because the guy who wired it all up (my old boss) was in a rush and just grabbed whatever cable was long enough -- or as the case may be, far, far too long. He then left the shit laying on the floor.

    It was such a mess that when I started working on it, I pulled out about a half-dozen cables that didn't connect to anything at either end, I shit you not.
     
  18. midcalbrew

    midcalbrew OT Supporter

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    *sigh* ... our racks are such a clusterfuck I'm hoping for a meteor strikes so we can rewire everything. Tiny downtime windows plus no overtime means the mess remains.
     
  19. Mike99TA

    Mike99TA I don't have anything clever to put here right now

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    Hooray for working at a company that has a department dedicated to cabling. When we order a cable(s) for a server(s) we come back a few days later and there are cables hanging inside the rack. All we have to do is plug them in. :big grin:

    However at my last job I had to not only run the cables myself but cut and crimp them all... when we moved to a new datacenter me and 2 other guys custom made 756 cables (total length 32,000 feet), and then ran them all underneath a raised floor and up a bunch of different racks.
     
  20. makaze

    makaze New Member

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    I love running cables at our facility.. its been so many years and there are so many unused cables under the floor.
    It looks like a giant rats nest. So bad one department put a ladder overheard to redo all their wiring to make it organized. I say probably 10 to 20 years of wires ran and left to die underground :( One day someone will have to clean them up.
     
  21. deusexaethera

    deusexaethera OT Supporter

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    Dude, I'm salaried. I did all this work on my own time. I still feel good about it.
     
  22. deusexaethera

    deusexaethera OT Supporter

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    You should really pull those out and take them to a wire recycler. Seriously, copper is expensive enough now that you'll probably come out ahead even if the company has to pay for the time you spend doing it.
     
  23. deusexaethera

    deusexaethera OT Supporter

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    That's cool. I have a 33-50% success rate making my own cables, so at a couple bucks apiece, I convinced my boss it would cost less to buy premades from Newegg. I'd have never gotten it done if I'd had to make my own cables too.
     
  24. Mike99TA

    Mike99TA I don't have anything clever to put here right now

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    33-50% success rate? How do you manage that? I think out of the ~760 cables we made, only maybe 30 tested bad, and we just put the crimper back over the heads and crimped extra hard and they were good to go. Unless you're just flying through them without ever double checking anything I don't see how you could mess up more than 1 in 10 or so.

    FWIW cabling yourself isn't always cheaper (especially if you have to get specially rated cable for going into ceilings, etc) - but its nice to be able to make the cables the exact length needed.
     
  25. deusexaethera

    deusexaethera OT Supporter

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    Maybe my crimper is shitty, or maybe my cable tester is too sensitive, I dunno, but about 1 in 4 cable ends that I attach, at least one wire doesn't conduct properly. Whatever, though, I don't need exact lengths of cable, so the mass-produced ones are good enough for me.
     

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