Using Totalview on RTC

12-Dec-2007

Introduction

Totalview is a powerful, sophisticated, and programmable tool that lets you debug, analyze, and tune the performance of complex serial, multiprocessor, and multithreaded programs. In order to use the Totalview debugger on rtc.rice.edu, follow the steps below. NOTE: Totalview is licensed to run on a maximum of 8 processors. Debugging on more than 8 processors will not work.

How to Run Totalview

The following steps describe how to run Totalview on a compute node on RTC.

1. Login to rtc.rice.edu

If you are using a Unix or Linux desktop, login to RTC with this ssh command:

ssh -X rtc.rice.edu

2. Start VNC server

Once logged in, start the VNC server with the vncserver command:

rtcuser@rtchost:~> vncserver

The first time vncserver is run from your account, you will be prompted to establish the VNC environment:

rtcuser@rtchost:~> vncserver

You will require a password to access your desktops.

Password:
Verify:
Would you like to enter a view-only password (y/n)? n

New 'X' desktop is rtchost:1

Creating default startup script /home/rtcuser/.vnc/xstartup
Starting applications specified in /home/rtcuser/.vnc/xstartup
Log file is /home/rtcuser/.vnc/rtchost:1.log

NOTE: In this example, the X desktop name is "rtchost:1" and will likely be different each time you run vncserver. The display server hostname is "rtchost" and the display number is "1". These values will be important in future steps.

3. Start VNC viewer

Once the VNC server is running, on the same login node or any other login node, start the VNC viewer with the vncviewer command:

rtcuser@rtchost:~> vncviewer

A small graphical dialog box will appear and prompt you for the VNC server. Enter the server name (X desktop name) that you created in step #2 above. In our example, it will be rtchost:1. Then enter the password you specified in step #2 when prompted. Upon successful login to your VNC server, an X window with a xterm should appear on your desktop. This is an X windows session running on RTC.

4. Initialize the Totalview environment

Inside the xterm window that appeared in step #3, load the Totalview module (assuming bash is your default shell):

module load totalview

5. Run Totalview on an interactive compute node with PBS

To run Totalview, you will need to run it on an interactive compute node:

qsub -I -V -q interactive -l nodes=2,walltime=00:30:00

Once you have received a prompt on a compute node, set your DISPLAY environment variable to be the VNC server you established in step #2 (assuming bash as your default shell):

DISPLAY=rtchost:1
export DISPLAY

Now run your application with the Totalview debugger.

mpiexec -tv ./mpi-application

The Totalview debugger should appear inside your X windows session running via VNC. Once the graphical interface is running, proceed to step 6 below.

6. Modify Totalview preferences to use SSH instead of RSH to begin debug session

Totalview will need to be configured to use SSH instead of RSH.
On the top Totalview toolbar go to File -> Preferences -> Launch Strings and change the "%C" to /usr/bin/ssh.
Then click OK
Click GO to begin debugging.

7. Terminate VNC when finished

When you are finished using Totalview, close your X windows VNC session and then make sure that Xvnc has been killed on the login node where you started the server on step #2 by running the following command.

rtcuser@rtchost:~> vncserver -kill :<display number>

NOTE: <display number> is the display number from step #2 above.

Getting More Help (User's Guide)

To get more help and to see the Totalview user's guide published by the vendor, Etnus, please see their online documentation for version 7 of Totalview. Also please see our online tutorials section.