Join Ed Liberman for an in-depth discussion in this video Server form factors, part of Networking Foundations: Servers.
- [Instructor] When we use the term form factor when discussing any computing device or component, we're talking about its size, appearance or dimensions. The term, form factor, is typically used to differentiate one physical implementation of the same device or component from another. Now in the case of servers, we're talking about the size and dimensions of the enclosure in which the server exists. So the first type of form factor I want to talk to you about is something called a rack mount.
Now a rack mount server is one that's been designed to be bolted into a frame, which we refer to as a rack. Now these servers come in standard sizes and fit into standard rack slots or bays. Now they also require the use of something called a rail kit. And a rail kit when implemented allows you to slide the server in and out of the rack for maintenance. Now some of the benefits of using a rack to hold a server like this is to get the server up off the floor, that's better for if it floods.
Another might be to just for not having to bend over when working on it for maintenance. It allows for very efficient use of space. And maintains good air circulation. There are definitely some good benefits to the rack mount server. Now I mentioned that they come in standard sizes and fit into these standard bays. So you need to know that the way these dimensions are referred to is 1U, 2U, and even though I don't have it listed here, there is technically a 3U, it's just not common.
And then 4U. So the three common ones are 1U, 2U and 4U, which basically, 1U is the smallest, thinnest, 2 is the mid-range and 4 is the largest. Now the one other thing I want to talk to you about when it comes to rack mount servers is understanding that we really need to figure out a solution for all the cables. And the reason why is 'cause if you think about it, if you're gonna slide the server in and out of the rack, then the cables have to be long enough to be able to pull the server all the way out without disconnecting them from whatever else they are attached to.
But, the flip side of that is that when you push the server back in, you don't want big, long cables dangling in the back. So, we use something called Cable management arms which are nifty little tracks that are designed to hold longer cables and do it in a way that when you push the server back in the cables kind of fold up nicely behind the server. You can almost think of it kind of like an accordion.
Where when you pull it out straight, you get this big, long straight thing, and you push it in together, it kind of folds together. So the second form factor that I want to talk to you about is something called the tower form factor. Now this is the form factor that you are most likely most familiar with because this is exactly how many workstation computers or even home PCs are housed, alright? Now you don't typically find a whole lot of towers in a rack in a server room.
You'll typically find these towers just sitting on the floor or maybe on some kind of a shelf, things like that. They do technically make rails so that if you have, let's say, a big chunk of space in the bottom of a rack, you can actually wheel the tower in and out. But otherwise, you don't typically find it. You just find it kind of laying around. Now a couple things about the tower. First of all, it comes in many different sizes. If you've ever shopped for a computer you know that you see mini-tower and mid-tower and full-sized tower, there's many different sizes of towers.
Servers typically are gonna be in your full-sized towers. Again, typically this is the form factor you find more on the client side of things than the server side of things. And where you will find it used as a server is primarily in smaller businesses that only have a need for one or two servers and therefore don't have the need for a sophisticated server room with racks and racks of servers. Now the last form factor that I want to talk to you about is one that's called the blade form factor.
Servers can actually come in blade form. And this is a technology that consists of a server chassis housing multiple, thin, modular circuit boards known as Server blades. Each blade or very often they're just called a card, will still contain a processor, memory, network controllers, other input, output devices just like any server would need to have. But, this is a way to make it that a server can experience a great reduction in size and cabling and everything else over the use of a tower server.
But even, believe it or not, over your typical rack mount server as well. Now when it comes to the blade enclosure, it's a system that houses multiple blade servers and the chassis of this enclosure provides power and cooling to the blade servers. Now one other thing to know about this enclosure is that the back plane provides a connection point for the blade servers in that blade enclosure, right? So you picture you're kind of shoving the blade in and it makes a connection in the back.
But there are also some back planes that are constructed with slots on both sides. And in this case, they're located in the middle of the enclosure and they're referred to as a mid-plane. So that's something just to kind of to understand about the blade enclosure. So those are the three main form factors that you will find your servers in. And it's important that you understand the benefits and the pitfalls of each and know the technologies that go with them so that you can make an adequate decision when putting together a server room for your organization.
- Server components and server architecture
- Basic configuration
- Server roles
- Asset management
- Server storage
- Server security
- Backup and recovery