Provided by: openmpi-bin_4.1.5-3ubuntu1_amd64 
NAME
ompi_info - Display information about the Open MPI installation
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 http://www.open-
mpi.org/community/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 handfull 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:
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.
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.
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:
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.
Detailed
This sub-category is for parameters that are generally useful, but users probably
won't need to change them often.
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
ompi_info
Show the default output of options and listing of installed components in a human-
readable / prettyprint format.
ompi_info --parsable
Show the default output of options and listing of installed components in a machine-
parsable format.
ompi_info --param btl tcp
Show the level 1 MCA parameters of the "tcp" BTL component in a human-readable /
prettyprint format.
ompi_info --param btl tcp --level 6
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 --parsable
Show the level 1 MCA parameters of the "tcp" BTL component in a machine-parsable
format.
ompi_info --type string --pretty-print --level 3
Show the level 3 MCA parameters of string type in a human-readable / prettyprint
format.
ompi_info --path bindir
Show the "bindir" that Open MPI was configured with.
ompi_info --version
Show the version of Open MPI version numbers in a prettyprint format.
ompi_info --all
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.
AUTHORS
The Open MPI maintainers -- see http://www.openmpi.org/ or the file AUTHORS.
This manual page was originally contributed by Dirk Eddelbuettel <edd@debian.org>, one of
the Debian GNU/Linux maintainers for Open MPI, and may be used by others.