A CentOS Net Install (CentOS NetInstall) is basically installing from a very small downloaded ISO image which downloads the needed files to complete the full operating system installation on-the-fly. This documentation explains the process of installing CentOS using the HTTP NetInstall method. This method is much faster for basic systems since you don't have to download 4-6 ISO files or one huge DVD based ISO just to get started. If you are installing many systems you may want to look into the stand-alone DVD as it will save time in the end.

Downloading NetInstall ISO

First you must download the NetInstall ISO from your favorite mirror based on your specific system requirements. Depending on your system requirements you will have to choose the proper architecture type. For example, i386 is used on most standard computers where as x86_64 is used if your hardware can support 64bit. You can get a list of mirrors for your location by checking out the CentOS mirrors list. Many times you will have to find a mirror that offers ISO images. For this example, I will be using CentOS i386 architecture.

Download i386: http://mirror.chpc.utah.edu/pub/centos/6.0/isos/i386/CentOS-6.0-i386-netinstall.iso

Download x86_64: http://mirror.chpc.utah.edu/pub/centos/6.0/isos/x86_64/CentOS-6.0-x86_64-netinstall.iso

Mirrors List: http://www.centos.org/mirrors/

Burning the ISO Image to Prepare for Installation Process

After you burn the ISO to a CD you can boot from it to begin the setup. You will have to get through a few steps using the graphical install process. For example, you will need to choose your language and setup your network so the box can access the Internet. I have seen issues with the Manual IP Configuration so if you have DHCP for this step choose Dynamic IP Configuration to make your life easier. Choose HTTP as the setup option when asked for an installation method.

Configure TCP/IP

Choose Installation Method

During the HTTP Setup you will need to enter in the web site name and CentOS directory information. Make sure you make the proper changes for your platform and other requirements. You may need to change the directory based on your OS version and architecture type.

Website Name: mirror.centos.org
CentOS Directory: centos/6.0/os/i386 or centos/6.0/os/x86_64

Installation Process

In conclusion, the whole process took less than 30 minutes. That includes downloading and burning the NetInstall ISO image as well as running a full LAMP install. The process that took the most time was downloading the stage image after the process has started.. The CentOS NetInstall continues to save much time. If your machine is not equipped with the ability to read DVD disks this is a great option.