Install Cinnamon, LightDM to CentOS 7 Minimal Install

yum install -y epel-release
yum groupinstall "X Window System"
yum install -y cinnamon gnome-icon-theme-legacy.noarch
yum groupinstall Fonts

(execute this command as a ordinary user / not as root)
echo "exec /usr/bin/cinnamon-session" >> ~/.xinitrc

yum install -y lightdm
systemctl set-default graphical.target# rm '/etc/systemd/system/default.target'
# ln -s '/usr/lib/systemd/system/graphical.target' '/etc/systemd/system/default.target'
# systemctl enable lightdm.service
# startx

When resume from hibernate, all open applications always gone.
If I switched to text mode by pressing Ctrl+Alt+F2
then pm-hibernate or systemctl hibernate,
the applications will still alive.

So Here is how I fix it:

vi /etc/systemd/system/display-manager.service
[Service]
;Restart=always


Thanks
http://centoshowtos.org/desktop/cinnamon-on-centos-7/
http://unix.stackexchange.com/questions/181503/how-to-install-desktop-environments-on-centos-7
http://jensd.be/?p=125