Hi Our Redhat Linux server was working fine for last 2 weeks. Last day we found that, GUI was not opened after booting . After displaying the message "No printer defined" it was stopped. We can move to any terminal from Ctrl+Alt+F1 to Ctrl+Alt+F6. But the GUI Ctrl+Alt+F7 is not possibleto open. Then we run Xconfigurator. After that when we execute startx it shows the following error Fatal server error: Can't read lock file /tmp/.X0-lock When reporting a problem related to a server crash, please send the full server output, not just the last messages. Please report problems to xfree86@xxxxxxxxxxxx giving up. xinit: No such file or directory (errno 2): unable to connect to X server xinit: No such process (errno 3): Server error. We went to the directory /tmp and run the command " ls -a" it shows that --> "ls: .X0-lock: Input/output error " We can not rename the file, delete the file , change the attribute of the file. At the time of rebooting it also shows file /tmp/.X0-lock can not be deleted : input/output error So it is not possible to run GUI. What will we do ? Please reply as early as possible. Sourajit