NAME

       orte-dvm, ompi_dvm - Establish a Distributed Virtual Machine (DVM).

       Note:  orte-dvm  and ompi-dvm are synonyms for each other.  Using either of the names will
       produce the same behavior.

SYNOPSIS

       orte-dvm [ options ]

       Invoking orte-dvm via an absolute path name  is  equivalent  to  specifying  the  --prefix
       option  with  a  <dir> value equivalent to the directory where orte-dvm resides, minus its
       last subdirectory.  For example:

           % /usr/local/bin/orte-dvm ...

       is equivalent to

           % orte-dvm --prefix /usr/local

QUICK SUMMARY

       orte-dvm will establish a DVM that can be used to execute subsequent applications. Use  of
       orte-dvm  can  be  advantageous,  for example, when you want to execute a number of short-
       lived tasks. In such cases, the time required to start the ORTE DVM can be  a  significant
       fraction  of  the time to execute the overall application. Thus, creating a persistent DVM
       can speed the overall execution. In addition, a  persistent  DVM  will  support  executing
       multiple  parallel  applications  while  maintaining  separation  between their respective
       cores.

OPTIONS

       -h, --help
              Display help for this command

       -V, --version
              Print version number.  If no other arguments are given, this will also cause  orte-
              dvm to exit.

       Use  one of the following options to specify which hosts (nodes) of the cluster to use for
       the DVM.

       -H, -host, --host <host1,host2,...,hostN>
              List of hosts for the DVM.

       -hostfile, --hostfile <hostfile>
              Provide a hostfile to use.

       -machinefile, --machinefile <machinefile>
              Synonym for -hostfile.

       --prefix <dir>
              Prefix directory that will be used to set  the  PATH  and  LD_LIBRARY_PATH  on  the
              remote node before invoking the ORTE daemon.  Setting MCA parameters:

       -gmca, --gmca <key> <value>
              Pass  global  MCA  parameters  that  are  applicable  to all contexts. <key> is the
              parameter name; <value> is the parameter value.

       -mca, --mca <key> <value>
              Send arguments to various MCA modules.  See the "MCA" section, below.

       -report-uri, --report-uri <channel>
              Print out orte-dvm's URI during startup. The  channel  must  be  either  a  '-'  to
              indicate  that the URI is to be output to stdout, a '+' to indicate that the URI is
              to be output to stderr, or a filename to which the URI is to be written.

       The following options are useful for developers; they are not  generally  useful  to  most
       ORTE and/or MPI users:

       -d, --debug-devel
              Enable debugging of the ORTE layer.

       --debug-daemons-file
              Enable debugging of the ORTE daemons in the DVM, storing output in files.

       There may be other options listed with orte-dvm --help.

DESCRIPTION

       orte-dvm  starts a Distributed Virtual Machine (DVM) by launching a daemon on each node of
       the allocation, as modified or specified by the -host and -hostfile options.  Applications
       can  subsequently be executed using the orte-submit command.  The DVM remains in operation
       until receiving the orte-submit -terminate command.

   Specifying Host Nodes
       Host nodes can be identified on the orte-dvm command line with the -host option  or  in  a
       hostfile.

       For example,

       orte-dvm -H aa,aa,bb ./a.out
           launches two processes on node aa and one on bb.

       Or, consider the hostfile

          % cat myhostfile
          aa slots=2
          bb slots=2
          cc slots=2

       Here, we list both the host names (aa, bb, and cc) but also how many "slots" there are for
       each.  Slots indicate how many processes can potentially execute  on  a  node.   For  best
       performance,  the  number  of slots may be chosen to be the number of cores on the node or
       the number of processor sockets.  If the hostfile does not provide  slots  information,  a
       default  of  1  is  assumed.   When  running under resource managers (e.g., SLURM, Torque,
       etc.), Open MPI will obtain both the hostnames and the number of slots directly  from  the
       resource manger.