PAR Technologies PARASTATION5 V5 - Manual (Page 24)

Using the ParaStation5 queuing facility
20 ParaStation5 Administrator's Guide
a predefined node list. If not defined, all currently known nodes are taken into account. Also, the variables
PSI_NODES_SORT , PSI_LOOP_NODES_FIRST , PSI_EXCLUSIVE and PSI_OVERBOOK are observed.
Based on these variables and the list of currently active processes, a sorted list of nodes is constructed,
defining the final node list for this new task.
Beside this environment variables, node reservations for users and groups are also observed. See
psiadmin(1).
In addition, only available nodes will be used to start up processes. Currently not available nodes will be
ignored.
Obeying all these restrictions, the processes constructing a parallel task will be spawned on the nodes
listed within the final node list. For SMP systems, all available CPUs (cores) on this node may be used for
consecutive ranks, depending on the environment variable
PSI_LOOP_NODES_FIRST .
For administrative tasks not requiring a dedicated CPU (core), e.g. processes
spawned using pssh, other strategies take place. As this type of processes are
intended to run on dedicated nodes, predefined by the user, the described procedure
will be circumvented and the processes will be run on the user-defined nodes.
For a detailed discussion of placing processes within ParaStation5, please refer to process placement(7),
ps_environment(5), pssh(8) and mpiexec(8).
5.4. Using the ParaStation5 queuing facility
ParaStation is able to queue task start requests if required resources are currently in use. This queuing
facility is disabled by default. It can be enabled by each user independently. All requests of all users are
held within one queue and managed on a first-come-first-serve strategy.
For details, refer to ParaStation5 User's Guide.
5.5. Exporting environment variables for a task
ParaStation by default exports only a limited set of environment variables to newly spawned processes,
like
HOME , USER , SHELL or TERM .
Additional variables can be exported using PSI_EXPORTS .
For a complete list of environment variables known to and exported automatically by ParaStation, refer to
ps_environment(5) .
For more details, refer to ParaStation5 User's Guide.
5.6. Using non-ParaStation applications
It is possible to run programs linked with 3rd party MPI libraries within the ParaStation environment.
Currently supported MPI1 compatible libraries are:
• MPIch using ch_p4 (mpirun_chp4)
• MPIch using GM (mpirun_chgm)
• InfiniPath (mpirun-ipath-ps)
• MVAPIch (mpirun_openib)
• QsNet MPI (mpirun_elan)