My First Rack and Rails

Notice: Page may contain affiliate links for which we may earn a small commission through services like Amazon Affiliates or Skimlinks.

Samir

Post Liker and Deal Hunter Extraordinaire!
Jul 21, 2017
3,311
1,484
113
49
HSV and SFO
So I've been working with PCs since the late 1990s and only recently was able to purchase my first server--an HP DL380 G5 (it was cheap). This came with rails mounted to it, but I didn't have a rack.

Well, when I purchase my second cheap server (Dell 2950), it came with a short floor standing rack that looks identical this one, sans wheels:
Norco R4-15U 15U 4 Post Open Frame Steel Rack - Newegg.com

So now I finally have a rack, and a rack mount server with rails, but I cannot seem to find any real instructions on how the rails need to mount to the rack. :oops: The HP rack kit is HP part# 359254-001, but I can't seem to find a manual for it.

I've gotten to the point that I've separated the server from the rails that need to be mounted to the rack, but mounting those to the rack is where I'm stuck. I can't seem to figure out how it is designed to attach securely to the rack. :oops:

Any assistance and guidance appreciated!
 
  • Like
Reactions: gigatexal

WANg

Well-Known Member
Jun 10, 2018
1,308
971
113
46
New York, NY
So I've been working with PCs since the late 1990s and only recently was able to purchase my first server--an HP DL380 G5 (it was cheap). This came with rails mounted to it, but I didn't have a rack.

Well, when I purchase my second cheap server (Dell 2950), it came with a short floor standing rack that looks identical this one, sans wheels:
Norco R4-15U 15U 4 Post Open Frame Steel Rack - Newegg.com

So now I finally have a rack, and a rack mount server with rails, but I cannot seem to find any real instructions on how the rails need to mount to the rack. :oops: The HP rack kit is HP part# 359254-001, but I can't seem to find a manual for it.

I've gotten to the point that I've separated the server from the rails that need to be mounted to the rack, but mounting those to the rack is where I'm stuck. I can't seem to figure out how it is designed to attach securely to the rack. :oops:

Any assistance and guidance appreciated!
Okay - first, take a deep breath and don't panic. Racking is not that hard.
First, some preliminary information.

Each "U" is defined with a height of 1.75 inches, or 45mm. The rack width is standardized at 19 inches, or 482.6 mm. Those 2 dimensions will never change. The depth (the distance between the front and the rear of the server) of the rack is variable, since you could have deeper or shallower racks depending on the rack manufacturer, and that's why the racking kits on the server will telescope (gets longer or shorter) to compensate for different racks in the market.



If you look at each side of the server rack you should typically see square or circular holes running down each pillar - they are arranged typically in groups of 3, like s0. Every 3 holes make up a U. Your rack are fitted with square holes.



Good server racks (like APC Netshelter) typically have markings denoting the U position, like so - as long as you pay attention, you will do just fine. Sometimes servers come with a cardboard rack ruler to help measure things out.



Next, look at the ends of your rail. How does the rail secure onto the provided holes, and how do you mount the server onto the rack once you are done?
So that depends on the rail family you are dealing with, and whether you got one of those fancier Enterprise servers, or a cheap no-frills server.
For example, here is the ends of a typical Dell ReadyRail set that I deal with:


Notice that the rail ends have hardware pre-placed, so all you do is open up the rail so it'll fit the depth of the server rack, figure out which U you are dealing with, and just place it on in both the front and the back - there is usually a interlocking mechanism on them to keep one side of the rack from falling out once you place it on, and all rails have screws or latches to keep the rail from telescoping back open once you have it in place. With these setups you typically do not need additional reinforcements. The weight of the server and the interlocking will keep the server rack from falling out.


In some cheap server racks (Whitebox vendors like Infotrend or SuperMicro are guilty of that) you'll need to directly screw the rack into place. In this case, you'll need a partner to hold the rails on the front while you work on the back, or vice versa. If none are available, that's why Velcro tie-wraps exist to make temporary slings. Oh yeah, how do you screw something into a square hole? Cage nuts - they go on the inner edge of the rack. Here's what they look like:


Rack nuts are held in place by the top and bottom flanges and are to be mounted on the side facing away from where the rack will go. You count off the top and bottom of each U, and pop them on/off as you see fit - it depends on the screw positioning on the rack - it's often 4 on each side. They are the bane of my existence as an admin as they are a pain to install/remove, and often fall into places where you cannot reach them (like an underfloor conduit).

Okay, so what does that have to do with your specific case? So here's a photo of your rack. There's a pair of inner rails, a pair of outer rails, and usually a set of screws if it is delivered with original packaging (make sure you don't throw it away. I had to scream at plenty of "Smart hands" coloc engineers for losing mounting screws in my past). You'll need a long Phillips head screwdriver, a calm and patient mind, a spare pair of hands (belonging to a helpful partner) or some velcro tie-downs if your spare hands are not available. The orientation looks correct. The rail on "top" is the right side (when you are on the front of the rack facing backwards). the one next to it are the left side rack (the orientation is typically engraved onto the metal).

First things first. The inner rails (if required) need to be mounted on the server via flathead Phillips screws. It should be short travel (around 4mm) and in the bag. Look at this diagram for a generic idea of what needs to be done:


Then you'll need to mount the outer rails to the rack and secure it. Something like this:



See, every manufacturer is slightly different when it comes to how their outer rails interface with the rack. Some are just clips. Some are actually just a bunch of holes on a metal flange, requiring you to put in rack nuts. Judging by the photo, looks like your rack already have the hardware pre-placed, so no need for rack nuts and all that unpleasantries. The 4 studs on each outer rail (2 in the front, 2 in the back) should go into the square holes and stay in place. Then you just lock the middle and call it a day.
Here's a youtube video of someone mounting a Proliant G6 2U server. Your G5 rack is a little different in that the bar runs across the bottom U, so orientation matters here. But it's generally the same principle - rack one end, go to the back, rack the other end, lock the middle, add cable management arm if present, then rack the server.

Grab a buddy and have him/her hold one end while you work on the other (Or if not, feed a velcro tie-wrap to one of the U holes and make a temporary mount sling). Just remember that the rails go on the inner edge and presents a continuous surface for the inner rail (mounted to the server) to slide against. Make sure that the Us are even and all on the same level. If your rack is unmarked, get a silver marker and delineate each U triplet - you'll thank yourself later.


Make sure that the racks are even and on the same Us throughout (trust me, make sure. Dropping a Cisco Catalyst 4507 was one of the accidentally not-funny things that you'll not want on your job history, as me and an ex-coworker from a previous gig can/will attest.

Once you are sure, put some boxes under the rack (just in case you are not sure and don't want to take the gamble), and then slide the server in.
Here's a generic look of what it should look like:


Oh yeah, I should mention that not every server rail set will have removable or discrete inner rails. The Dell ReadyRails have their inner rails integrated into the rail set - they can slide out but not all the way. To mount them, telescope the outer rails open to mount the rails to the rack (correct U and all that), then latch it to prevent it from telescoping back open. Then pull the inner rails out all the way until it reaches the limit. on the top of the rail you should see 4 captive notches, which corresponds to 4 pegs on the chassis itself. Hold the server up until all 4 pegs align with the notches, place it down and into the notch, and then once it engages the inner rail, push the entire thing back in. The R620 that I admin at work are mounted like that - good stuff.

Alright. Hope that was helpful. Good luck.
 
Last edited:

Samir

Post Liker and Deal Hunter Extraordinaire!
Jul 21, 2017
3,311
1,484
113
49
HSV and SFO
Motion to sticky that. Great content.
Second that motion. :)

THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU

Not only did you cover the basics (alot of which I knew), but you led me right to where I was getting stuck--mounting the rails. And thanks to the video link, I think I may have an idea of exactly how to do it. I only need to check my outer rails to see how it locks them from extending once mounted since my rack's depth isn't that much, but the server is a full 36". Otherwise, looks like I'm never having to learn the pain of cage nuts. :D

I've been online in forums for decades now, and this is almost hands-down the most helpful computer how-to post I've ever seen. Thank you for taking the time to write it (complete with pictures!) and making my day. :)
 
  • Like
Reactions: Tha_14

Samir

Post Liker and Deal Hunter Extraordinaire!
Jul 21, 2017
3,311
1,484
113
49
HSV and SFO
I got it! :D

These rails for the g5 are pretty nice--no screws on the server side as they lock on some tabs that are either there or were installed previously. And on the outer rails, they have clips which engage with the rack on both ends so there's no locking the outer rail's length via any mechanism. Pretty easy once I knew what to look for.

So now the question is--should it have been that hard to slide my server onto the rails and then into place? :confused: I even triple-checked the heights of the rails at all four locations and it's all the same height. I even measured the height using a measuring tape in case I reassembled my rack wrong after disassembling it for transport. Everything is at the same height but it definitely didn't slide smooth like a kitchen drawer--it's more like that stubborn kitchen drawer that will break if you yank on it too hard. :eek:
 

WANg

Well-Known Member
Jun 10, 2018
1,308
971
113
46
New York, NY
That's dependent on the age of the rails and how heavy the machine just so happened to be. The G5s are old machines (we are up to G10/G11 these days), so I don't expect them to be entirely smooth. Like I said, if you are a little weary, spray some lithium grease or WD-40 on the server rails, and support the server by putting a few boxes underneath.
 
Last edited:

Samir

Post Liker and Deal Hunter Extraordinaire!
Jul 21, 2017
3,311
1,484
113
49
HSV and SFO
It's a decent chunk--think of the same weight as the Dell 2950. Easily 50lbs. Plus the rails didn't seem to have any grease or bearings on them. I'm happy that it's working as we speak and looks stable as I checked the rails before placing the server. :cool:
 

Samir

Post Liker and Deal Hunter Extraordinaire!
Jul 21, 2017
3,311
1,484
113
49
HSV and SFO
I didn't know the site had a 'Guides' forum until today. I nominate this thread or just the post by WANg to be moved to that forum. :) Thank you mods/admins!