While the way in which you debug IBM Blue Gene MPI programs is identical to debugging these programs on other platforms, starting TotalView on your program differs slightly. Unfortunately, each machine is configured differently so you’ll need to find information in IBM’s documentation or in documentation created at your site.
In general, either launch mpirun under debugger control or start TotalView and attach to an already running mpirun. For example:
TotalView tells mpirun to launch TotalView Debug Servers on each Blue Gene I/O node.
Because I/O nodes cannot resolve network names, TotalView must pass the address of the front-end node interface to the servers on the I/O nodes. This is usually not the same interface that is used to connect to the front-end node. TotalView assumes that the address can be resolved by using a name that is:
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The systems at the IBM Blue Gene Capacity on Demand follow this convention. If you are executing programs there, you will not need to set the TotalView variables described in the rest of this section.
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If the front-end cannot resolve this name, you must supply the name of the interface using the –local_interface command-line option or by setting the bluegene_io_interface TotalView variable. (This variable is described in the "TotalView Variables" of the TotalView Reference Guide.)
Because the same version of TotalView must be able to debug both Power-Linux programs (for example, mpirun) and Blue Gene programs, TotalView uses a Blue Gene-specific server launch string. You can define this launch string by setting the bluegene_server_launch_string TotalView variable or command-line option.
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You must set this variable in a tvdrc file. This differs from other TotalView launch strings, which you can set using the File > Preferences Dialog Box.
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The default value for the bluegene_server_launch_string variable is:
In this string, %L is the address of the front-end node interface used by the servers. The other substitution arguments have the same meaning as in a normal server launch string. These substitution arguments are discussed in Chapter 7 of the TotalView Reference Guide.