xhost fix for oracle linux 7 or all linux servers

when you run installer and get "DISPLAY not set. please set the DISPLAY and try again"

simply follow these steps it works. my target was to login to oracle in order to install oracle database 12c

1) Log on to oracle linux as root
2) Open a terminal
3) echo $DISPLAY    (get this value you have to use it after login to oracle my case it was :0)
4) enter 'xhost +'
5) enter 'su - oracle'
6) enter 'export DISPLAY=:0'
7) runInstaller (or use whatever installer is required)

if you are have an option to use any other terminal then putty i will use mobaxterm, you dont need to do all these  settings in order to run GUI interface.

oracle linux 7 at oracle VM VirtualBox 5.0.6 connecting to internet

oracle linux 7 at oracle VM VirtualBox connecting to internet

once you have installed Oracle Linux 7 at VirtualBox and you are tying to connect to internet in  order to run Rpm or something else you need to enable Ethernet.

this button is at the Top Right corner of VirtualBox 5.0.6 next to the speaker button. click and Enable one port it will let you connect to internet.