Join Scott Simpson for an in-depth discussion in this video Installation options, part of Up and Running with CentOS Linux.
If you're installing CentOS from scratch, you'll need to start with an installation image. You can download an installer from centos.org/download. At the time that I'm recording this, there are two buttons on the screen for ISO images, a DVD image which is around 4 gigabytes and will fit on a 4 gig flash drive or a DVD-R, and the Everything ISO, which includes more packages, and is about 6.6 gigabytes which would require an 8 gig flash drive or dual layered DVD-R. You download these images through your browser or you can get a torrent download as well.
I've already downloaded the DVD ISO onto my system. There are a couple of other ISO images available as well. To check those out, I'll click on the mirrors link here. And I'll find a mirror close to me. I'll choose one at the University of Southern California. If you choose a mirror near you, it's likely that you'll get a faster download speed. There's an HTTP link for all of the mirrors, and an FTP and rsync link for many of them. I'll click on the HTTP link, since I'm already using a web browser. Here is a list of all of the files the USC is hosting on their mirror.
Lots of old versions of CentOS, the gpg keys for verifying the ISO images, and here, under 7.0.1406, I'll find the current version. I'll click ISOs and x86_64, the only architecture available for CentOS anymore. The Read me file here lists the differences between the different images. There's the basic DVD image. A net install image that has a small download but then looks for all of the installation packages on the network. The everything image that I mentioned before and two live images featuring the GNOME and KDE desktop environments.
These come with some productivity software and are intended for evaluation or a temporary or emergency use. You can start your computer up with one of these images to use and evaluate CentOS without modifying your computer's hard drive. The last option is called Live CD, which is similar to the GNOME live image but is small enough to fit on a CD. This can be handy if you need the boot disk to travel with. Though, keep in mind that these live images will be slower than a native install because chances are, whatever media you're running them from is slower than a built-in hard disk.
These text files contain the hashes of each image, in case you need to verify that the image you downloaded hasn't been modified. Because CentOS is used for a wide variety of things, there are many different configuration options when you first set it up. If you're installing from scratch, on a physical or virtual machine, you can pick one of many different configurations. If you're using an installation of CentOS on a Cloud service such as Digital Ocean or Amazon, you'll typically be limited to whatever options the image provider has decided to offer to start out. Let's take a look at the Base Environments offered out of the box.
You don't need to memorize these or write them down. They show up in the installer that we'll see later on. But I want to give you an idea of what's available before we start installing. The Minimal install offers what CentOS calls Basic functionality. This is a command line environment with pretty basic tools. It's a good place to start if you're deploying a very customized or very lean environment where you want to only specifically install what you want to have. Infrastructure server is similar to a basic environment in that it offers command-line functionality.
And during the installation process there are options to install packages to make it a backup server, DNS server, directory client, directory server, email server, ftp server, file server, database server, print server, load balancer and more. You can also add support for virtualization, hardware monitoring, and high availability. File and print server is a command line environment and configures packages for those services. Basic Web Server starts out with packages for being a web server and allows you to add various languages and database options during the install.
Virtualization Host is available to set the machine up for being a VM Hypervisor. Server with GUI sets the machine up with a desktop environment and allows you to choose various packages to support different server roles. GNOME Desktop and KDE Plasma Workstations configure the machine to have a GUI of either type, and offer the opportunity to install Internet and productivity applications. Development and Creative Workstation allow the installation of graphics, development, writing, and productivity tools during install.
These base environments are starting points for installations. You can add, remove, and modify packages and groups of packages later on as well.
- What is CentOS?
- Installing CentOS
- Configuring networking with DHCP or a static IP
- Connecting remotely
- Working with SELinux
- Setting up a firewall
- Setting up a web server
- Connecting to shared folders
- Launching the graphical user interface (GUI)