Hi All,
Pretty straightforward question. I have a new 25U rack and am buying, building and installing equipment overtime.
Right now, for at least a few weeks, I’ll have only a 5U gaming PC rackmount case to put in. Do I just slide into the bottom and go up from there?
Thanks!
If you’ve got a rack mounted UPS that usually goes at the bottom, because it’s probably very heavy and you don’t want it to squish you. It also makes the rack harder to tip over if you’re not going to bolt it to the floor.
Networking gear typically goes at the top. I’m not sure if there’s a reason for that beyond convention.
Other than that, I guess just go nuts.
Thanks for the reply! I have heard that advice about UPS (and generally just heavier stuff goes on the bottom as you said to anchor the rack down).
But I guess my question is this will be built over time, should everything go on the bottom first? Or really only if its super super heavy like a UPS?
Also I should mention this is a 4 post rack
Actually, there is. In them olden days network cable to a rack in a DC usually came from the ceiling, from special cable ducts. So it made sense to have the networking gear in the top of the rack, also to avoid cluttering up access to servers and/or other gear by network cables destined for switching gear in a lower part of the rack.
Nowadays, cabling from the floor is a valid choice too, with raised floors actually making this pretty easy.
As for your rack, despite 25U not being very tall, do consider bolting it to the floor or the wall to avoid any tipping risks. More so if you use sliders for your gear for easy access.
HTH!
Thank you for the reply!
I guess I’m still wanting to know…where in the rack should I place this first 5U computer?
The arguments for placing network gear make a lot of sense in a data center setting (that’s why they’re common).
Allow me to argue that a different strategy may be beneficial for home use.
The common convention is to bring in a bundle of point-to-point cables into the rack (top or bottom), fix connect them to a distribution panel (typically open to the front) and run cables from there to switches and nodes as necessary.
My 42U rack is on casters and easily moved (on concrete floor in the basement). That provides easy access to the back of the rack in my situation.
I live in an old house that doesn’t come with any built-in network cabling. To minimize runs of long cables I only run a single cable per room having a number of small desktop switches as necessary. It turns out that in all my cases the devices that require network connectivity are bundled together naturally, so this makes sense.
As a result I have only a few (less than a handful) of cables coming into the rack.
At this point I have about a dozen devices located in the rack requiring network connections.
I have been thinking about cable management a bit and at this point (not saying I cannot be convinced otherwise or that this is set in stone) I mount my enterprise switch in the middle of the rack facing backwards.
As a result I only need to deploy minimal cable lengths to devices in the rack and I have a reasonable clean path of cables reaching the rack from the rest of the house. The latter is setup with sufficient slack allowing free movement of rack on the casters.
Highly unconventional, but I figured worth sharing to someone starting out. Not necessarily as a recommendation, but to open OPs mind allowing to think clearly about needs and wants.
I would go for easiest access. E.g. You may not want to bend all the way down to access your first 5U computer in case that is happening frequently.
I also would not shy away from moving devices inside your rack in the future.
Please note, that if you consider using a UPS to leave space on the bottom of the rack. These really should be placed low for reasons explained above.
Thank you kindly for your post!
Sounds good! I eventually want to get a UPS…so I may put this 5U in the top or near it I suppose. Like you said nothing is permanent in a rack so if I have to move stuff Im fine with that.
Usually the structured wiring (patch panel / networking switch) goes in at the very top followed by the modem / router then your pc(s) then your ups as @redocbew mentioned.
At least this is how I’ve seen them done.
Actually, I think it’s the opposite. In the olden days every single DC had to have raised floors… IBM mainframes until rather recently would only accept intake air from underneath. These days, every piece of DC equipment is front intake, so there’s less compelling reason for the expense of a raised floor.
There’s also big, big wiring differences… In the olden days, computers would be hooked up to a LOT of cables. Serial cables, coax cables, all manner of proprietary equipment cables, etc., and having some of those under the floor, while others run over-head, made a lot of sense. Now… how many cables do you need going into your DC cage? A single internet fiber and a single cross-connect could be faster and can do everything you could possible need…
As for wiring… if you lease a cage in a proper shared data center, the floor tiles are going to be bolted down and require an appointment for staff to open them up for you. So top exit holes in racks and cable ladders are still very much a thing.
The most likely reason for top-of-rack switches was the assumption that many of the connections are not for use in the local rack, but instead will go out the top, so why waste the cable manager space for those?
If that’s not the case, and the switches are mostly used for in-rack connections, right in the middle of the rack is the best spot… minimizing cable length, reducing the size of cable bundles in the vertical cable management by up to half, etc.
I’ve previously shared my strong (educated) opinions on how rack cable management should be done:
Also, the switches and netork patch panels usually point out the back of the rack, as that is where the wiring for the servers in that rack is anyway. If the rack is all network gear then the stuff can face out whatever way is convenient for the room.