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6.1 Important Environment Variables

There are many environment variables and command line flags that can be set to influence the operation of POE tools and the execution of parallel programs. A complete list of the POE environment variables can be found in the IBM ``AIX Parallel Environment Operation and Use" manual. Some environment variables which critically affect program execution are listed below.

MP_PROCS - sets number of processes, or tasks, to allocate for your partition. Often one process, or task, is assigned to each node, but you can also run multiple tasks on one node.

MP_RESD - specifies whether or not the Partition Manager should connect to the POWERparallel system Resource Manager to allocate nodes. If the value is set to ``no,'' the Partition Manager will allocate nodes without going through the Resource Manager.

MP_RMPOOL - sets the number of the POWERparallel system pool that should be used by the Resource Manager for non-specific node allocation. This is only valid if you are using the POWERparallel Resource Manager for non-specific node allocation (from a single pool) without a host list file.

Information about available pools may be obtained by typing the command jm_status -P at the Unix prompt.