In this recipe, we will learn how to initiate the process of running a netinstall over HTTP (using the URL method) in order to install CentOS 7. It is a process in which a small image file is used to boot the computer and let the user select and install only the software packages and services he wants and nothing more over a network connection thus providing great flexibility.
Before we begin, it is assumed that you already know how to download and checksum a CentOS 7 installation image and how to create the relevant installation media from it. For this recipe here, we will need to download and create installation media for the netinstall image (download the latest CentOS-7-x86_64-NetInstall-XXXX.iso file) instead of the minimal ISO shown in another recipe in this chapter. Also, it is assumed that you have at least gone through the graphical installation procedure once to exactly know how to boot from your installation media and work with the installer program.
To begin this recipe, insert your prepared netinstall media, boot your computer from it, and wait for the welcome screen to appear:
http://
textfield, which we will use to download all the required installation packages at http://mirror.centos.org/centos/7/os/x86_64/.install.img
file. This may take several minutes to complete, but once resolved, a progress bar will indicate all the download activity. When this process finishes successfully, the exclamation mark at the installation source will go away but another one will pop up which will tell the user that it is missing the software selection. Click on it and choose whatever fits your need. As for the purpose of this recipe, just select Minimal install under Base environment and then click on Done.The purpose of this recipe was to introduce you to the concept of the CentOS network installation process, in order to show you just how simple this approach can be. By completing this recipe you have not only saved time by limiting your initial download to those files that are required by the installation process, but you have also been able to take advantage of the full graphical installation method without the need for a complete DVD suite.