How to use screen in DevStack OpenStack

1)
List all screen sessions of current user
#screen -ls



2)
Howto Attach to a not detached screen session.
#screen -x

3)
Reattach to a screen session
#screen -r session_id_or_name

4)
To see all commands or parameters on screen.
Ctrl + a, Then Press ?

5)
Detach/Exit from a screen session
Ctrl + a, Then Press d

6)
Kill a screen session
Ctrl + a, Then Press Shift + k

7)
How to move to next screen window/tab in a screen session
Ctrl + a, Then Press n

8)
How to move to previous screen window/tab in a screen session
Ctrl + a, Then Press p

9)
How to list name of all screen windows/tabs and select from there
Ctrl + a, Then Press Shift + '

10)
How to Toggle  to  the  window/tab  displayed  previously
Ctrl + a, Then Ctrl + a again

11)
How to copy logs from screen
* To start the copy mode, use Ctrl + A, Then Press [
* To start copying, press Enter
* Select the text using arrow keys
* Again press Enter to stop selction and copy to clipboard
* To exit the copy mode, use Ctrl + A, Then Press ] or Ctrl + C

12)
How to restart a service
After doing any changes in the code, if you wish to restart a service,
* Goto the window/tab of the service, then use Ctrl + C to stop that service.
* To start the service, use the UP arrow key to move to the command which used to start the service and press Enter.

* This way, we can't restart horizon service, you need to restart apache web server
#service apache2 restart