For starters, we'll need to get our hands on Ubuntu Server and then create bootable installation media in order to install it. How you do this largely depends on your hardware. Does your server have an optical drive? Is it able to boot from USB? Refer to the documentation for your server in order to find out. In most cases, it's a very good idea to create both a bootable CD and USB media of Ubuntu Server while you're at it. That way, regardless of how your server boots, you're most likely covered.

Unfortunately, the differing age of servers within a typical data center introduces some unpredictability when it comes to how to boot installation media. When I first started with servers, it was commonplace for all servers to contain a 3.5 inch floppy disk drive, and some of the better ones even contained a CD drive. Nowadays, servers typically contain neither and only ship with an optical drive if you ask for one nicely while placing your order. If a server does have an optical drive, it typically will go unused for an extended period of time and become faulty without anyone knowing until the next time someone goes to use it. Some servers boot from USB; others don't. In order to continue, check the documentation for your hardware and plan accordingly. Your server's capabilities will determine which kind of media you'll need to create.

Thankfully, we only need to download a single file in order to create our media, regardless of whether or not we plan on creating USB or CD media. To get started, navigate to http://www.ubuntu.com/ in your browser, which will bring you to the main site for Ubuntu. On the top right, there will be a download button, and if you hover your cursor over that, you'll see an option for the Server version. Alternatively, you can simply Google Ubuntu Server and it should be the first result, or close. Just make sure the URL in the search result has a domain of ubuntu.com before you click on it. The file that you download will be an ISO file, ending with a .iso file extension. This is an image file that we will later use to create bootable media.

When this book was written, Ubuntu Server 16.04 is the most recent version. Depending on when you're reading this, the next release, 16.10 (or newer) may also be available. So, on the Ubuntu website, you may have a choice between LTS and non-LTS. Ubuntu 16.04 is Long-Term Support (LTS) while 16.10 is not. What does this mean? Essentially, whether or not an Ubuntu release is an LTS release determines the length of time it will be supported with security updates. Non-LTS releases are supported with security updates for just nine months, while LTS releases are supported for five years. This makes LTS releases perfect for servers, since it's not typical for an administrator to upgrade the entire distribution frequently. Non-LTS releases can be very handy for testing code on a newer software stack, but that's the only reason I can think of to consider a non-LTS release on a server. When in doubt, stick with LTS.

If you're setting up a virtual machine, then the ISO file you download from the Ubuntu download site will be all you need. In that case, all you should need to do is create a VM, attach the ISO to the virtual optical drive, and boot it. From there, the installer should start, and you can proceed with the installation procedure contained within this chapter. Going over the process of booting an ISO image on a virtual machine differs from hypervisor to hypervisor, so going over the process on each would be beyond the scope of this book. Thankfully, the process is usually straight-forward and you can find the details within the documentation of your hypervisor or from performing a quick Google search.

As I mentioned before, I recommend creating both a bootable USB and bootable CD. This is due to the fact that you'll probably run into situations where you have a server that doesn't boot from USB, or perhaps your server doesn't have an optical drive and the USB key is your only option. In addition, the Ubuntu Server boot media also makes great recovery media if for some reason you need to rescue a server. To create a bootable CD, the process is typically just a matter of downloading the ISO file and then right-clicking on it. In the right-click menu, you should have an option to burn to disc or similar. This is true of Windows, as well as most graphical desktop environments of Linux when a disc burning application installed. If in doubt, Brasero is a good disc burning utility to download for Linux.

The exact procedure differs from system to system, mainly because there is a vast amount of software combinations at play here. For example, I've seen many Windows systems where the right-click option to burn a CD was removed by an installed CD/DVD burning application. In that case, you'd have to first open your CD/DVD burning application and find the option to create media from a downloaded ISO file. As much as I would love to outline the complete process here, no two Windows PCs typically ship with the same CD/DVD burning application. The best rule of thumb is to try right-clicking on the file to see if the option is there, and if not, refer to the documentation for your application. Keep in mind that a "Data Disc" is not what you want, so make sure to look for the option to create media from an ISO image or your disc will be useless.

Creating a bootable USB is a bit more involved but easier to outline in steps, since each platform has a generally agreed upon method of creating them. In Linux, we can use ddrescue, or simply dd, while in Windows we can use the Universal USB installer from http://www.pendrivelinux.com/. In later section in this chapter, I'll outline the procedure of creating a bootable USB in Windows, Linux, and Mac.