Rack Systems – CompTIA Network+ N10-006 – 5.7

A data center can contain many different rack types and configurations. In this video, you’ll learn about two-post racks, four-post racks, server rails, temperature and airflow, rack monitoring, and security.
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If you look around your data center. You may see that your equipment is installed in different kinds of racks. One very simple rack is a two-post rack. This is usually where you would put smaller equipment and telecommunications equipment. If you have servers or larger pieces of equipment, you’re probably going to use a four-post rack. These are freestanding racks, and you’re able to connect the devices on all four corners of the rack.

Some racks might even include server rails, especially when you have a lot of devices in a very high density area, so that you can slide those servers out and slide them back in on rails instead of having to unscrew from the rack and remove them completely every time you wanted to work on them.

Here’s a data center that has a combination of two-post and four-post racks. You can see the two-post rack here very close to the front of this picture. And the four-post racks you can see are in the rest of the room. And you can see all of the servers and even the servers on rails that are connected to these four-post racks. Here’s a close-up of some of the rails. You can see the rails on the left and right side. So this allows the administrator to go around to the front and slide the entire server out to be able to open it up, work on the inside, or swap it out very easily.

One of the big concerns you have in a data center is being able to keep all of this equipment cool. So it’s a combination of your heating, ventilation, and air conditioning systems, combined with what we call hot aisles and cold aisles, within a data center. This is a cross section of a data center. You can see on the left and right sides I have the heating, ventilation, and air conditioning systems. They’re taking hot air from the ceiling, cooling them, and putting cool layer down underneath all of the systems in this raised floor.

And then you have all of the server racks. Notice the server racks are designed to put equipment so that cool air is being pulled in from one side of the rack. And it’s heating up that air and pushing it out to the outside of the rack. Our hot aisles are connected to each other. You can see there’s a hot aisle, there’s a hot aisle, and there’s another hot aisle. The hot air then goes to the top of the ceiling and the entire process begins itself again.

If you walk into a data center, you’ll sometimes see that the hot aisles and the cold aisles are very well delineated. In this particular case, you can see there is this sheeting that’s over the cold aisles. And every other aisle, of course, is the hot aisle, where the warm air is being blown out and being sent to the top of the ceiling where the entire process begins again.

You’ll find a number of different monitoring systems inside of a data center. You may find environmental sensors so that you’ll know the temperature and humidity inside of the data center. We’re also including webcams these days so that we can see the equipment and look at the lights that may be in front of the devices that are installed in our data center. Very often these are integrated with our enterprise management systems so we can go to one screen and see all of the environmental controls and web cams all on one page.

Data centers are often very secure environments as well. We want to limit access to the devices themselves, so the racks are usually closed in with keys. We’ll usually have blocks and even fences and gates separating different parts of the data center from others.

Here’s a data center that has these closed racks, and you can see that every single one of these doors has a key with a lock on it. In this particular case maybe not so secure since someone has left the key on the rack. But you get the idea of how you can restrict access to all of these components while still making sure that they’re able to operate normally inside of the data center.