How to silence that messages box?
I give you two alternatives:
- Ctrl+Alt+F1 to get yourself to a text console and then carry on with your RAID recovery.
- SSH into the server from your workstation.
Honestly, those are your options.
As I inferred above, Xorg/Gnome/KDE/whatever have no place on a linux server. Even the likes of Microsoft have (finally) figured that servers and GUIs are not good bedfellows, and are racing as quickly as possible to strip out as many GUI elements as possible from their server operating systems. If you have an X11 application that you need to run (I see this frequently with commercial linux backup packages. Symantec Netbackup and the like), do so via X11 forwarding, not on the console itself.
You likely don't want to hear this answer, but I give it nonetheless, as it's the right answer.