First: Install software into your system, command like:
sudo apt-get install openssh
Second: Download nxclient/nxnode/nxserver from http://www.nomachine.com/download.php, and install them step by step, command like:
sudo dpkg -i ***.deb
Third: Edit /etc/ssh/sshd_config, and modify or add "AuthorizedKeysFile %h/.ssh/authorized_keys2 " [this is very important], and restart ssh service, command like:
sudo service ssh restart
Fourth: Ok, preparatory work is completed. Run nx client and connect server, it will get some errors. So, we must configure something.
Fifth: Edit "/usr/NX/etc/server.cfg", like these:
EnableUserDB = "1"
EnablePasswordDB = "1"
Sixth: Edit "/usr/NX/etc/node.cfg", like these:
CommandStartGnome = "/usr/bin/gnome-session --session=gnome-classic"
Seen from /usr/share/gnome-session/sessions/ direcotry , I found that I could choose gnome or gnome-classic or gnome-fallback or ubuntu-2d and ubuntu for “gnome-session --ssesion=” option.
Seventh: Restart you NX server, command like:
sudo service nxserver restart
Eighth: Run nx client, choose UNIX and GNOME, press login. GOOD LUCK!