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I'm new here, and looking for some suggestions on how to design my rack. I have a chance to tidy up my server room and got a green light on server downtime for 24 hours this weekend. Below is my inventory.

  1. 2x 48U compaq racks (no provision for adding vertical managers what so ever)
  2. 35x 2U servers
  3. 4x 1U servers
  4. 2x 48port cisco 1G ethernet switch (3750)
  5. 1x Cisco 1941w router
  6. 1x Juniper 40 port 10G switch (ex4500)

How can I wisely position them in the racks so that any cabling after wrapping them with zip ties looks neat. And what should I start off with? Wwitches and network cables first and then mounting servers and connect those cables? And when I Googled I saw some people positioning the switches on the back of the rack. Is this OK?

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    Photographs, please? – ewwhite Sep 25 '15 at 16:01
  • Neither answer mentions checking if you have reversible fans for your switches but you don't mention hot/cold isles – Jacob Evans Sep 26 '15 at 5:02
  • If ever there was a usage-case for blades... – Chopper3 Sep 26 '15 at 15:49
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It's not possible to give you more than a few guidelines/suggestions:

  • You don't say anything about power! What have you got for UPSes, PDUs? Power cables are harder to work with than network cables, so I'd make sure power distribution is taken care of first.

  • Your servers have their network ports on the back, so mounting the switch on the back makes cabling a lot simpler. You miss out on watching the blinking lights, however...

  • Get lots of different lengths of patch cables, suitably colour-coded.

  • Use lots of velcro. You can add some cable ties at the end to lock some things in place.

  • Google "cable porn" to see some examples of what you want your installation to look like when you're done.

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Here is my recommendation based on my experience:

  1. Put the switch at the top of the rack, at the back, with the ports facing the back door. This is so you can wire your server to it easily.

  2. Don't use zip ties! Use velcro. Buy cut-to-length roll and use liberally. Why not zip ties? Because the day you'll want to move a cable, change something, you'll swear at your zip ties. Of course you can cut them and put new ones on, but it's much simpler to un-tie the velcro, run your additional cable and tie it back in, etc.

  3. Keep your power cables away from network. Run power first.

  4. Before putting in your cables, put your servers in. Look at the power plugs, network plugs, etc. See how they align (or not) and visualize how you can run your cables to maximize untangleness.

  5. Label every cable. I find that having cables with simple numbers work ok but that having more descriptive labels helps a lot more. Example, a network cable could have, at the switch end, To serverX, and at the server end, To port X.

You can check this from ServerFault blog. How we upgrade a live data center

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