Hi,
Thanks for all the replies. I have tried some of the suggested methods from different people. The following is my experience:
a. Ctrl+alt+backspace, this may be the first choice. However, one time it did not work and the system frozen and cannot log in remotely.
b. I tried to change from run level 5 to 3, which did not work as I can not find /etc/rc.d/rc.4 file in RedHat 6.5. After change back from level 3 to 5, the workstation stuck with a frozen during startup and can not restart normally. Then I restarted to single user mode and it took me a few hours to fix the startup problem.
I searched the internet, and found the following methods that may be very helpful:
4 Ways to Recover From a Crashed or Frozen X Server on Linux<
http://www.howtogeek.com/119293/4-ways-to-recover-from-a-crashed-or-frozen-x-server-on-linux/>
http://www.howtogeek.com/119293/4-ways-to-recover-from-a-crashed-or-frozen-x-server-on-linux/
I tried the method mentioned in the above link and used the following steps if ctrl+alt+backspace not work:
a. Ctrl+alt+F1 to switch to virtual console.
b. Alt+Sysrq+r to take the keyboard away from the control of the X server.
c. Ctrl+alt+F7 go back to x server (if you cannot go back, you can remote login to kill the X server by
ps -e | grep X and kill -9 all of them. You may also try alt +sysrq +k. Then you can go to log in again.
Sysrq may be like Stop-A in Soralis workstation. We need to use it very carefully.
In a normal situation, you may just wait for experiment to finish and restart the workstation.
However, there are some situations that we don't want to restart the workstation and kill the experiment. For instance, the MAS spin is still running, but we get a black screen unfortunately.
As the black screen is not happen too frequently. I am not to sure if the above method may work all the times. Hope this solve the problem.
Best regards,
Guoxing
Guoxing Lin, Ph.D.
NMR Facility Manager
Chemistry Department
Clark University
Email:glin_at_clarku.edu<mailto:glin_at_clarku.edu>
Tel: 508-793-7488
From: Guoxing Lin [mailto:GLin_at_clarku.edu]
Sent: Tuesday, February 09, 2016 1:33 PM
To: 'ammrl_at_ammrl.org' <ammrl_at_ammrl.org>
Subject: AMMRL: Red hat black screen after logout
Hi,
Our VNMRJ 3.2 is operated in Red Hat 6.4 or 6.5. We have encountered the following problem. Sometimes after we logout, we cannot get back to the login screen. The screen displays some message and is frozen. We had to restart the workstation.
Do you have any idea how to fix this problem?
Thanks!
Guoxing
Guoxing Lin, Ph.D.
NMR Facility Manager
Chemistry Department
Clark University
Email:glin_at_clarku.edu<mailto:glin_at_clarku.edu>
Tel: 508-793-7488
Received on Tue Mar 22 2016 - 09:49:04 MST