Servers and rails are literally made for each other. At the end of the day, rails are usually the most tightly fitting, cost effective way to fill up a rack of servers. Still, some people want to save that cost and wonder: why can’t you mount a server without rails?
Why you should mount servers with rails
When server manufacturers design a rack mount chassis, they include holes for shoulder screws and nuts. This feature has long been the standard because it created the most space efficient method of mounting when attached to server rails.
J-slots, or keyhole slots, occupy the inner rails and act as a convenient location to lock shoulder screws into. When installed with this method, servers cannot be accidentally removed because of pressure on both of the outer rails and the connection in the keyhole slots.
Universal rails are a bit different, but still a great way to rack your server. When purchasing these, you’re trading the shoulder screw/keyhole slot locking design for the ability to use the rail for any server within a range of dimensions. Throughout upgrades, these will save you money and time.
Basically, there’s a reason server rails are so commonly used. They protect your equipment and are the most space-conserving way to rack a server. None the less, there are valid alternative methods for mounting.
Mounting your server on a desk without rails
Let’s say you only have one or two servers and don’t want to buy an entire rack. This is an ideal situation for a Rack-to-Tower Conversion Kit that does not require rails.
Any trusted server manufacturer makes their components sturdy enough for the server to be on its side and still function. A Rack-to-Tower Converter does just that – allows you to run a server as if it were a PC tower.
The tower-style mounting configuration doesn’t require rails because of its adjustable stand assemblies. These lay flat on the table and clamp around the bottom of your upright server.
It’s that simple. After installation, you will be able to use your server as if it were a PC.
Don’t stack your servers on top of each other
Even our server rails, some of the highest quality on the market, are barely rated to hold two servers off the strength of a single rail. Servers cost too much money to risk mounting them improperly.
For instance, our 1U Universal Rack Rails is rated for 45 lbs. A 1U, dual CPU server server from ASA computers weighs about 26 lbs. It would simply not be safe for the servers to stack one on top of another without its own rail.
Of course, just because something is rated for a certain weight capacity doesn’t mean it will break instantly when carrying a couple more pounds of weight. What it does mean is that it wasn’t designed to handle that weight long term. Without testing it yourself you will be taking a risk that could affect your data and hardware investments.
Why not mount the server by its ears?
Some servers come with a hole through the ears that looks like it could possibly be used for mounting. These holes are actually for thumb screws which lock the server in place.
It can be confusing since thumb screws lock into the same holes that rails and shelves are mounted to. The most obvious difference is that shelves and rails mount into the top and bottom of a U space rather than the middle.
That being said, there are sleek 2 post rail kits for shallow servers. These kits will allow your server to hang off the back of a 2 post rack as if it were mounted by the server ears, but actually offers stability.
One of the main reasons you shouldn’t mount your server by its ears is because they are designed to secure the server, not mount it. Looking through forums, it appears that some people have gotten away with mounting through them, but most recommend against it. IT equipment is expensive and it’s just not worth the risk.
An alternative to using rails on a 2 post rack
If you are uncomfortable using a rail to mount your server on a 2 post rack, the best alternative is a shelf. 2 post rack shelves often have higher weight capacities than 2 post rails because they distribute weight more evenly.
A good example of this is the RackSolutions 2 Post Relay Rack Shelf. With a depth of 29 inches and height of 3U, it is rated to hold 300 lbs of equipment. This shelf will fit most full sized servers and sufficiently support their weight even on a 2 post rack.