mpiexec(1) HYDRA mpiexec(1)
NAME
mpiexec - Run an MPI program
SYNOPSIS
mpiexec args executable pgmargs [ : args executable pgmargs ... ]
where args are command line arguments for mpiexec (see below),
executable is the name of an executable MPI program, and pgmargs are
command line arguments for the executable. Multiple executables can be
specified by using the colon notation (for MPMD - Multiple Program
Multiple Data applications). For example, the following command will
run the MPI program a.out on 4 processes:
mpiexec -n 4 a.out
The MPI standard suggests the following arguments and their meanings:
-n <np>
- Specify the number of processes to use
-host <hostname>
- Name of host on which to run processes
-wdir <working directory>
- cd to this one before running executable
-configfile <name>
- file containing command-line options. The lines are of the
form separated by the colons in the commandline form: mpiexec
{<option arguments>} : {...} : {...} : ... : {...} Lines
beginning with # are comments, and lines may be continued by
terminating the partial line with
.
The following options are reserved by the MPI standard, but they
are not supported by MPICH (hydra):
-arch <architecture name>
- Pick hosts with this architecture type
-path <pathlist>
- use this to find the executable
-soft <triplets>
- comma separated triplets that specify requested numbers of
processes (see the MPI-2 specification for more details)
-file <name>
- implementation-defined specification file
Additional arguments that are specific to the MPICH
implementation are discussed below.
The colon character ( : ) may be used to separate different
executables for MPMD (multiple program multiple data)
programming. For example, to run the program ocean on 4
processes and air on 8 processes, use:
mpiexec -n 4 ocean : -n 8 air
MPICH-SPECIFIC ARGUMENTS
MPICH implements a few process managers. Here we list a general set of
arguments that many of the implementations support. More detailed
options that are supported by a particular implementation, e.g. hydra,
are available via:
mpiexec -h
Many of the implementations of process managers in MPICH support the
following arguments to mpiexec :
-np <num>
- A synonym for the standard -n argument
-env <name> <value>
- Set the environment variable <name> to <value> for the
processes being run by mpiexec
-envnone
- Pass no environment variables (other than ones specified with
other -env or -genv arguments) to the processes being run by
mpiexec .
By default, all environment variables are provided to each MPI
process (rationale: principle of least surprise for the user)
-envlist <list>
- Pass the listed environment variables (names separated by
commas), with their current values, to the processes being run
by mpiexec .
-genv <name> <value>
- The -genv options have the same meaning as their corresponding
-env version, except they apply to all executables, not just the
current executable (in the case that the colon syntax is used to
specify multiple executables).
-genvnone
- Like -envnone , but for all executables
-genvlist <list>
- Like -envlist , but for all executables
-usize <n>
- Specify the value returned for the value of the attribute
MPI_UNIVERSE_SIZE .
-l - Label standard out and standard error ( stdout and stderr )
with the rank of the process
-maxtime <n>
- Set a timelimit of <n> seconds.
-exitinfo
- Provide more information on the reason each process exited if
there is an abnormal exit
ENVIRONMENT VARIABLES FOR MPIEXEC
The following environment variables are understood by some versions of
mpiexec . The command line arguments have priority over these; that
is, if both the environment variable and command line argument are
used, the value specified by the command line argument is used.
MPIEXEC_TIMEOUT
- Maximum running time in seconds. mpiexec will terminate MPI
programs that take longer than the value specified by
MPIEXEC_TIMEOUT .
MPIEXEC_UNIVERSE_SIZE
- Set the universe size
MPIEXEC_PORT_RANGE
- Set the range of ports that mpiexec will use in communicating
with the processes that it starts. The format of this is
<low>:<high> . For example, to specify any port between 10000
and 10100, use 10000:10100 .
MPICH_PORT_RANGE
- Has the same meaning as MPIEXEC_PORT_RANGE and is used if
MPIEXEC_PORT_RANGE is not set.
RETURN STATUS
mpiexec returns the maximum of the exit status values of all of the
processes created by mpiexec .
LOCATION
/var/tmp/dMPbgpZE6a/mpich-4.3.2/src/pm/hydra/mansrc/mpiexec.txt
10/6/2025 mpiexec(1)
mpi 4.3.2 - Generated Thu Dec 4 07:47:25 CST 2025