SYNOPSIS

       ompi_info [options]

DESCRIPTION

       ompi_info  provides  detailed  information about the Open MPI installation. It can be useful for at least
       three common scenarios:

       1. Checking local configuration and seeing how Open MPI was installed.

       2. Submitting bug reports / help requests to the Open MPI community (see Getting help).

       3. Seeing a list of installed Open MPI plugins and querying what MCA parameters they support.

       NOTE:
          ompi_info defaults to only showing a few MCA parameters by default (i.e., level 1 parameters). Use the
          --level option to enable showing more options (see the LEVELS section for more information).

OPTIONS

       ompi_info accepts the following options:

       • -a, --all: Show all configuration options and MCA parameters. Also changes the  default  MCA  parameter
         level to 9, unless --level is also specified.

       • --arch: Show architecture on which Open MPI was compiled.

       • -c, --config: Show configuration options

       • -gmca, --gmca <param> <value>: Pass global MCA parameters that are applicable to all contexts.

       • -h, --help: Shows help / usage message.

       • --hostname: Show the hostname on which Open MPI was configured and built.

       • --internal: Show internal MCA parameters (not meant to be modified by users).

       • --level  <level>:  Show  only variables with at most this level (1-9). The default is 1 unless --all is
         specified without --level, in which case the default is 9. See the LEVELS section for more information.

       • -mca, --mca <param> <value>: Pass context-specific MCA parameters; they are considered global if --gmca
         is not used and only one context is specified.

       • --param <type> <component>: Show MCA parameters. The first parameter is the type of  the  component  to
         display;  the  second  parameter  is  the  specific  component  to display (or the keyword all, meaning
         “display all components of this type”).

       • -t, --type: Show MCA parameters  of  the  type  specified  in  the  parameter.  Accepts  the  following
         parameters:  unsigned_int,  unsigned_long,  unsigned_long_long,  size_t,  string, version_string, bool,
         double. By default level is 1 unless it is specified with --level.

       • --parsable:  When  used  in  conjunction  with  other  parameters,  the  output  is  displayed   in   a
         machine-parsable format --parseable Synonym for --parsable.

       • --path  <type>: Show paths that Open MPI was configured with. Accepts the following parameters: prefix,
         bindir, libdir, incdir, pkglibdir, sysconfdir.

       • --pretty: When used in conjunction with other parameters, the  output  is  displayed  in  “prettyprint”
         format (default)

       • --selected-only: Show only variables from selected components.

       • -V, --version: Show version of Open MPI.

LEVELS

       Open MPI has many, many run-time tunable parameters (called “MCA parameters”), and usually only a handful
       of them are useful to a given user.

       As  such,  Open  MPI  has  divided  these parameters up into nine distinct levels, broken down into three
       categories, each with three sub-categories.

       Note that since each MCA parameter is accessible through the MPI_T control variable  API  (introduced  in
       MPI-3.0), these levels exactly correspond to the nine MPI_T cvar levels.

       The three categories are:

       1. End  user:  Generally, these are parameters that are required for correctness, meaning that a user may
          need to set these just to get their MPI application to run correctly. For example, BTL if_include  and
          if_exclude parameters fit into this category.

       2. Application  tuner:  Generally,  these  are  parameters  that  can  be  used  to tweak MPI application
          performance. This even includes parameters that control resource exhaustion levels  (e.g.,  number  of
          free list entries, size of buffers, etc.), and could be considered “correctness” parameters if they’re
          set too low. But, really — they’re tuning parameters.

       3. Open MPI developer: Parameters in this category either don’t fit in the other two, or are specifically
          intended for debugging / development of Open MPI itself.

       And within each category, there are three sub-categories:

       1. Basic:  This  sub-category  is  for  parameters that everyone in this category will want to see — even
          less-advanced end users, application tuners, and new OMPI developers.

       2. Detailed: This sub-category is for parameters that are generally useful, but users probably won’t need
          to change them often.

       3. All: This sub-category is for all other parameters. Such parameters are likely fairly esoteric.

       Combining the categories and sub-categories, here’s how Open MPI defines all nine levels:

       1. Basic information of interest to end users.

       2. Detailed information of interest to end users.

       3. All remaining information of interest to end users.

       4. Basic information required for application tuners.

       5. Detailed information required for application tuners.

       6. All remaining information required for application tuners.

       7. Basic information for Open MPI implementors.

       8. Detailed information for Open MPI implementors.

       9. All remaining information for Open MPI implementors.

       By default, ompi_info only shows level 1 MCA parameters. To see more  MCA  parameters,  use  the  --level
       command line option.

EXAMPLES

       Show  the default output of options and listing of installed components in a human-readable / prettyprint
       format:

          ompi_info

       Show the default output of options and listing of installed components in a machine-parsable format:

          ompi_info --parsable

       Show the level 1 MCA parameters of the “tcp” BTL component in a human-readable / prettyprint format:

          ompi_info --param btl tcp

       Show the level 1 through level 6 MCA parameters  of  the  “tcp”  BTL  component  in  a  human-readable  /
       prettyprint format:

          ompi_info --param btl tcp --level 6

       Show the level 1 MCA parameters of the “tcp” BTL component in a machine-parsable format:

          ompi_info --param btl tcp --parsable

       Show the level 1 through level 3 MCA parameters of string type in a human-readable / prettyprint format:

          ompi_info --type string --pretty-print --level 3

       Show the “bindir” that Open MPI was configured with:

          ompi_info --path bindir

       Show the version of Open MPI version numbers in a prettyprint format:

          ompi_info --version

       Show all information about the Open MPI installation, including all components that can be found, all the
       MCA  parameters  that  they  support (i.e., levels 1 through 9), versions of Open MPI and the components,
       etc.:

          ompi_info --all

COPYRIGHT

       2003-2025, The Open MPI Community

                                                  Feb 17, 2025                                      OMPI_INFO(1)