How to Install GUI (Gnome 3) Using CD/DVD on RHEL/CentOS 7

As a Linux administrator for more than 6 yrs, I spend most of my time working on terminals, but there are some situations where I need a GUI instead of terminal. By default, RHEL/CentOS 7 server installed as minimal without any Graphical Desktop support. So, to install GUI on the top of minimal installation, we have two options:

1. The First method is, installing GUI (i.e. Gnome 3) using default base repository, it will download and install packages from Internet.
2. The second method is, installing GUI using RHEL/CentOS 7 ISO image via local CD/DVD device, this will avoid downloading of packages from internet.

The first method is time taking process, as it downloads packages from internet and install it on the system, if you have a fastest internet connection you can simply type the following command on the terminal to install GUI in no time.

# yum groupinstall "GNOME Desktop"        [On CentOS 7]
# yum groupinstall "Server with GUI"      [On RHEL 7]

But, those who have a slower connection, they can follow CD/DVD method, here the packages are installed from your local CD/DVD device, and the installation is much quicker than the first method.
Note: The installation instructions for GUI are same for both methods, but here our main goal is to avoid downloading of packages from internet and minimize time.
Those who are following CD/DVD method, they must have full RHEL/CentOS 7 DVD ISO (download and burn image to CD/DVD) with them, because we use this image to create a local yum repository. So that, during GUI installation, the packages are taken from your CD/DVD.
Note: For the demonstration purpose, I’ve used RHEL/CentOS 7 DVD ISO image to install Gnome 3, but the same instructions also works on RHEL 7 with minor changes in commands.

Step 1: Creating Local Yum Repository

1. Before creating a local yum repository, insert your CentOS 7 DVD ISO image your CD/DVD drive and mount it using the following commands.
First, create a empty ‘cdrom‘ directory under ‘/mnt/‘ location and mount the ‘cdrom‘ (/dev/cdrom is the default name of your device) under ‘/mnt/cdrom‘ path.

[root@tecmint ~]# mkdir /mnt/cdrom
[root@tecmint ~]# mount /dev/cdrom /mnt/cdrom

2. Once the ‘cdrom‘ mounted, you can verify the files under /mnt/cdrom using ls command.

[root@tecmint ~]# cd /mnt/cdrom/
[root@tecmint ~]# $ ls -l
total 607
-rw-r--r-- 1 tecmint tecmint     14 Jul  4 21:31 CentOS_BuildTag
drwxr-xr-x 3 tecmint tecmint   2048 Jul  4 21:29 EFI
-rw-r--r-- 1 tecmint tecmint    611 Jul  4 21:31 EULA
-rw-r--r-- 1 tecmint tecmint  18009 Jul  4 21:31 GPL
drwxr-xr-x 3 tecmint tecmint   2048 Jul  4 21:29 images
drwxr-xr-x 2 tecmint tecmint   2048 Jul  4 21:29 isolinux
drwxr-xr-x 2 tecmint tecmint   2048 Jul  4 21:29 LiveOS
drwxr-xr-x 2 tecmint tecmint 581632 Jul  5 15:56 Packages
drwxr-xr-x 2 tecmint tecmint   4096 Jul  5 16:13 repodata
-rw-r--r-- 1 tecmint tecmint   1690 Jul  4 21:31 RPM-GPG-KEY-CentOS-7
-rw-r--r-- 1 tecmint tecmint   1690 Jul  4 21:31 RPM-GPG-KEY-CentOS-Testing-7
-r--r--r-- 1 tecmint tecmint   2883 Jul  6 23:02 TRANS.TBL

3. Next, create a new local yum repository file under ‘/etc/yum.repos.d/‘ using your favorite editor, here I am using Vi editor.

On CentOS 7

[root@tecmint ~]# vi /etc/yum.repos.d/centos7.repo 

Add the following lines to it, save and quit the file.

[centos7]
name=centos7
baseurl=file:///mnt/cdrom/
enabled=1
gpgcheck=0

On RHEL 7

[root@tecmint ~]# vi /etc/yum.repos.d/rhel7.repo 

Add the following lines to it, save and quit the file.

[rhel7]
name=rhel7
baseurl=file:///mnt/cdrom/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

Some explanation about the above lines.

1. [centos7]: Name of the new repo section.
2. name: Name of the new repository.
3. baseurl: The current location of the packages.
4. Enabled: Enabled repository, value ‘1’ means enable and ‘0’ means disable.
5. gpgcheck: Check the signature of the packages, before installing them.
6. gpgkey: Location of the key.

4. Now, check the newly created local repository is available from yum repost list, but before that you must clear the yum cache and verify the local repo.

[root@tecmint ~]# yum clean all
[root@tecmint ~]# yum repolist all

Sample Output

[root@localhost Desktop]# yum repolist all
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: centosmirror.go4hosting.in
* extras: centosmirror.go4hosting.in
* updates: centosmirror.go4hosting.in
repo id                      repo name                            status
base/7/x86_64                CentOS-7 - Base                      enabled: 8,465
base-source/7                CentOS-7 - Base Sources              disabled
centos7                      centos7                              enabled: 3,538
centosplus/7/x86_64          CentOS-7 - Plus                      disabled
centosplus-source/7          CentOS-7 - Plus Sources              disabled
debug/x86_64                 CentOS-7 - Debuginfo                 disabled
extras/7/x86_64              CentOS-7 - Extras                    enabled:    80
extras-source/7              CentOS-7 - Extras Sources            disabled
updates/7/x86_64             CentOS-7 - Updates                   enabled: 1,459
updates-source/7             CentOS-7 - Updates Sources           disabled
repolist: 13,542

Note: Did you see in the above output highlighted in red color, that means our local repo is enabled and available to install packages.
But, you will also find multiple repositories are enabled in the above output, if you try to install any package it will take CentOS Base as default repository.
For example, let’s try to install ‘httpd‘ package using yum command.

[root@tecmint ~]# yum install httpd

Sample Output

============================================================================================================================================
Package                          Arch                        Version                                    Repository                    Size
============================================================================================================================================
Installing:
httpd                            x86_64                      2.4.6-18.el7.centos                        updates                      2.7 M
Installing for dependencies:
apr                              x86_64                      1.4.8-3.el7                                base                         103 k
apr-util                         x86_64                      1.5.2-6.el7                                base                          92 k
httpd-tools                      x86_64                      2.4.6-18.el7.centos                        updates                       77 k
mailcap                          noarch                      2.1.41-2.el7                               base                          31 k
Transaction Summary
============================================================================================================================================
Install  1 Package (+4 Dependent packages)
Total download size: 3.0 M
Installed size: 10 M
Is this ok [y/d/N]:

Note: You see in the above output, the package ‘httpd‘ is installing from CentOS base repository, even if you force yum to install packages from local repository by adding ‘–enablerepo‘ option, it still uses CentOS Base as its default repo. Give it a try and see the results, you will get same result as above.

[root@tecmint ~]# yum --enablerepo=centos7 install httpd

So, to install packages from our local repository, we need to use options ‘–disablerepo‘ to disable all repos and ‘–enablerepo‘ to enable centos7 or rhel7 repo.

Step 2: Installing Gnome 3 in RHEL/CentOS 7

5. To install GUI (Gnome 3) on RHEL/CentOS 7 minimal installation server, run the following yum command.

On CentOS 7

[root@tecmint ~]# yum --disablerepo=* --enablerepo=centos7 groupinstall "GNOME Desktop"

On RHEL 7

[root@tecmint ~]# yum --disablerepo=* --enablerepo=rhel7 groupinstall "Server with GUI"

The above command will install and resolve all the dependent packages using local repository, during installation it will ask for the confirmation press “Y” to continue..
6. When the installation finishes, make the system to boot automatically to the Graphical Interface, here we no more using ‘/etc/inittab‘ file to change runlevel, because RHEL/CentOS 7 switched to systemd and here we use ‘targets‘ to change or set default runlevels.
Run the following command to tell the system to boot Gnome Desktop automatically at system startup.

[root@tecmint ~]# ln -sf /lib/systemd/system/runlevel5.target /etc/systemd/system/default.target

7. Once you set the default ‘targets‘ for the GUI, now reboot the server to get into Gnome Desktop.

Install Gnome in RHEL/Centos 7

8. Once Gnome 3 installed, unmount the CD/DVD device.

[root@tecmint ~]# umount /mnt/cdrom