A server chassis is designed around its ability to be rack mounted. Over time, the industry adopted standards to make server rack installation easier for everyone. This is especially important to those who perform maintenance often or expand their server rooms.
So, if you know some of these standards, it won’t be too hard to rack a server. Learning the best practices of server mounting is important because you can lower risk of damaging components and ensure stability.
Before you install rails or shelves
- Be familiar with the dimensions of your server and rack. Before anything, you will need to know the mountable width, depth and height of your server. Afterwards, make sure that it your server compatible with the mounting width, depth and height of your rack.
In short, height is measured by rack units, which is equal to three holes on your rack. Width is usually 19 inches, there are very few exceptions to this standard. Depth is the most variable dimension of server racks and mounting equipment which is why rails and shelves usually have adjustable depth.
- If your server isn’t compatible with your rack, find an adapter that can help. Your full sized server will not mount on a 2 post rack without either an adapter kit or a 2 post / 4 post rail kit. Adapters can also help when your equipment isn’t wide enough for your rack or too deep / not deep enough.
- Know what type of holes your server rack has. Your rack will either have threaded, unthreaded or square holes. If you are using a tool-less rail or shelf, it will likely only work with a square hole rack. If you are trying to attach a threaded hole rail into a square hole rack, you will need to install cage nuts first.
- Adjust server rack shelves or rails to fit depth. Many rails and shelves produced in the past few years have adjustable depth. Unlike non-adjustable mounting equipment, these have a sliding mechanism that allows you to get an exact fit for your server. You will need to slide the rear bracket across the outer bracket of your rail or shelf to adjust the mounting depth.
How to rack a server
Mount the server rail or shelf in the rack. Once your depth is adjusted, you will now be able to mount your rails and shelves. Depending on the hole type of your rack and mounting mechanism of the equipment, instructions will be different. Here, we will link instructions on mounting with threaded, tool-less and square hole with cage nut variants.
Install inner rail into server via shoulder screws (for server specific rails). Rails that are specifically designed to work with servers like HP and Dell will have shoulder screws. These stick out of the sides of servers and look like little knobs. They attach to the j slot of the server rail to lock it in place and make it so that there is no metal on the top or bottom of the server.
Slide server into rack. If you are using a server specific rail, you will match the inner rails on your server up with the outer rails mounted on the rack and slide it in. If you are using a universal rail, you would not have installed anything to your server chassis and will be able to slide it onto the rail.
Install thumb screw if using a compatible server. Universal rails come with support for thumb screws which lock the server into the middle hole of a rack unit. Not all server chassis support thumb screws, but if yours does, it’s a good idea to use them.
Additional considerations before mounting
We’ve covered the basics so far, but planning ahead before your first installation is a critical part of setting up servers. The last thing you would want is to invest hundreds of dollars into a setup that won’t be adequate when you expand in the future.
There are ways to future proof your server rack such as making sure there’s room for mounting PDUs, Cable management and KVMs. You might also want to consider exclusively purchasing universal rails so that you can easily swap out equipment in the future.
Cable management will become increasingly important as you add more equipment to your rack. Horizontal and vertical cable management bars are the best accessories to keep cables tidy. Cables run down the horizontal bars until they exit or enter their destination through the vertical bars. There are tons of different methods to managing cables, but that is the general idea.
Fully fledged KVMs are able to switch between display outputs on several servers. This feature is a must depending on how large your server room is. Even if your setup only has one output, there are 1 port KVM consoles that fit in 1U of rack space. This can make your entire rack a stand alone setup with no outside displays or keyboards required.
Lastly, you should leave space to mount PDU. These can be installed in the front or rear end of your rack and provide power to your entire rack. They help consolidate cables further but will inevitably take up mounting space on the rack. You can either leave some space open to mount these or install them with a button mount adapter on your cable management bar.