When you first buy a server, you’ll probably get what’s known as a tower server. It’s in a case that looks very much like any other PC case. It might be a little sturdier than most, but otherwise it’s not that different.
As your computer infrastructure expands, you’ll start to acquire more hardware, like a big switch, a high-end firewall or security appliance, maybe a better phone system, another server or two along with a KVM so you can use the same keyboard/monitor/mouse, and a bigger UPS (uninterruptible power supply). Suddenly you have more equipment than space.
That’s when it’s time to look at getting a server rack. It allows you to store a lot of equipment in a small space.
Most business-class equipment can be mounted in a rack, although you may need a shelf for those tower servers you bought. When you upgrade them, look into a rack-mount server instead, which will be sized to fit into your rack. You may see terms like “1U,” “2U,” etc. These refer to the height of the equipment in your rack. The bigger the number, the bigger the equipment.
Keep your rack in a well-ventilated room to avoid trouble with overheated equipment. Racks pack equipment in tight, so keeping the server room cool is critical.
Racks also provide a level of security, as most can be locked. The ideal is to keep your rack in a locked server room, but in smaller offices where this isn’t an option, a locked rack (or even a shorter “half-rack”) will help.