How To Install GNOME GUI In CentOS 7 Linux
Install Gnome GUI packages using the YUM command.
# yum groupinstall "GNOME Desktop" "Graphical Administration Tools"
Enable GUI on system startup. In CentOS 7 / RHEL 7, systemd uses “targets” instead of runlevel. The /etc/inittab file is no more used to change run levels. So, issue the following command to enable the GUI on system start.
# ln -sf /lib/systemd/system/runlevel5.target /etc/systemd/system/default.target
Start The GUI
By default after installing the “GNOME Desktop” group of packages, the default target will not have changed, meaning that after a reboot the GUI will not automatically be loaded. We can check the current default target as shown below.
[root@centos7 ~]# systemctl get-default multi-user.target
The target is similar to the old run levels, in this case multi-user.target is equivalent to run level 3 meaning that after a reboot the GUI will not be loaded here. We instead set the default to the graphical.target which is equivalent to run level 5.
[root@centos7 ~]# systemctl set-default graphical.target Removed symlink /etc/systemd/system/default.target. Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/graphical.target. [root@centos7 ~]# systemctl get-default graphical.target
While this has changed the default target which is accessed during system boot, our current target is still the multi-user.target. We can change to the GUI by performing ‘systemctl isolate graphical.target’ which will change us to the GUI immediately.
[root@centos7 ~]# systemctl isolate graphical.target
Alternatively a system reboot would also work, as all future boots should boot to the graphical target by default.
Removing The GUI
If you’ve installed the GUI on a server and realized that it was a terrible mistake, don’t worry! We can also undo this by simply using yum to remove the “GNOME Desktop” package group
[root@centos7 ~]# yum groupremove "GNOME Desktop"
Carefully read through the packages that will be removed and ensure that this looks correct prior to removing packages or dependencies.