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:
- The First method is, installing GUI (i.e. Gnome 3) using default base repository, it will download and install packages from Internet.
- 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.
- [centos7]: Name of the new repo section.
- name: Name of the new repository.
- baseurl: The current location of the packages.
- Enabled: Enabled repository, value ‘1’ means enable and ‘0’ means disable.
- gpgcheck: Check the signature of the packages, before installing them.
- 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
