This is a summary of my reply to the person who posted the original query. I'd fallen off the list when my email address changed and the old address was no longer forwarded. But I was in touch and got the user running so I thought I'd pass on what I found. The original post reported problems starting TotalView with mpirun -tv This method appears to be broken currently. Looking at the 3.1.4 manual it looks like the documentation suggests other ways of starting TotalView. It has totalview -a mpirun -a -n 3 ./foo but then suggests you can use an 'indirect' launch with totalview mpirun -a -n 3 ./foo The first method is just wrong and won't work. The -a indicates that anything after the -a is an argument for the target program being debugged. This example has two '-a' with the first one before mpirun, so we don't see a program to debug. I think the behavior is undefined. The second method should work, but it does not invoke the 'indirect method'. Instead it is the 'classic' or 'direct' method. It will start up TotalView on mpirun, and when the job starts, it will attach to the processes that are launched. This method is tried and true, and it is scalable. I prefer a variation of this method which is totalview -args mpirun -np 3 ./foo. It's the same functionality, but you don't have to remember to place the -a after mpirun, and it allows one to get the mpirun command set up correctly, and then prepend totalview -args to it. The indirect method works as well, but is not scalable as it launches debug servers for each process rather than for each node. To start that one could simply type totalview or maybe totalview foo The first method will bring up the session manager, and you would choose to start a new parallel session. It will show a screen where you can pick the parallel starter. For MPICH 3.1, you could pick either MPICH2 or MPICH3, and they should work. MPICH will not, as that goes back to the original MPICH of the 1.2 era. Then pick the number of tasks. You may have to add the additional arguments of -f hostfile to run across different nodes, but I don't think setting the number of nodes really makes a difference. If you use 'totalview foo' the method is similar, but you need to go to the parallel tab to pick which parallel system you are using. If you want some help with updating the docs, just let me know. ;-) PeterT -- Peter Thompson | Principal Technical Support Engineer | Rogue Wave Software, Inc. Accelerating Great Code | P 508-652-7734 | F 508-652-7701 | www.roguewave.com / [email protected]