Introduction

In most instances, the Linux servers I setup are used to host the Oracle database software and only require using the Command-Line Interface (CLI) for the OS. This is beneficial because I only need to perform a minimal installation and can add only those required Linux packages (RPMs) needed to support the database. However, there are situations where I need to access a graphical desktop in order to install or run certain Graphical User Interface (GUI) applications.

This guide provides the steps needed to add the GNOME Desktop to a CentOS minimal installation where the OS was installed without the X Window System.

CentOS 6

In this section, the GNOME desktop will be added to a new server running CentOS 6.2 (x86_64) after performing a "Minimal" install.

Install Desktop Packages

# yum -y groupinstall "Desktop" "Desktop Platform" "X Window System" "Fonts"

You can also install the following optional GUI packages.

# yum -y groupinstall "Graphical Administration Tools" # yum -y groupinstall "Internet Browser" # yum -y groupinstall "General Purpose Desktop" # yum -y groupinstall "Office Suite and Productivity" # yum -y groupinstall "Graphics Creation Tools"

Finally, if you wanted to add the K Desktop Environment (KDE).

# yum -y groupinstall kde-desktop

When using yum groupinstall, the groupinstall option only installs default and mandatory packages from the group. There are times when you also want to include optional packages within a group. I have not figured out (yet) how to control which package types to install (group package "policy") from the command-line using yum. The only method I know of to also include optional packages is to edit the /etc/yum.conf file and add the following to the [main] section:

group_package_types=default mandatory optional

The reason I mention this is because I wanted to install "Terminal emulator for the X Window System" (xterm) which is under the group "Legacy X Window System compatibility". xterm happens to be an optional package and did not get installed until I addedgroup_package_types=default mandatory optional to /etc/yum.conf.

# yum -y groupinstall "Legacy X Window System compatibility"

I did find a plug-in for yum that allows users to specify which package types within a package group should be installed when using yum groupinstall.

http://projects.robinbowes.com/yum-grouppackagetypes/trac

Enable GNOME

Since the server was previously running on CLI mode, we need to change the initialization process for the machine to boot up in GUI mode.

Open /etc/inittab using a text editor and change following line:

id:3:initdefault:

To:

id:5:initdefault:

After making the change, reboot the machine.

# init 6

Note that you can switch from GUI to CLI mode manually by using following method:

GUI to CLI: Ctrl + Alt + F6CLI to GUI: Ctrl + Alt + F1

Installing Additional Applications

After logging in to the GNOME Desktop, you can now go to System > Administration > Add/Remove Software to manage application in CentOS.

By using this wizard, you can install various applications similar to yum but through a GUI. Applications installed using this method will appear in the Application menu list.