HP-MPI User's Guide (11th Edition)

Understanding HP-MPI
MPI options
Chapter 3 121
-commd Routes all off-host communication through daemons
rather than between processes.
Local host communication method
-intra=mix This same functionality is available through the
environment variable MPI_INTRA which can be set to
shm, nic, or mix. Use shared memory for small
messages. The default is 256k bytes, or what is set by
MPI_RDMA_INTRALEN. For larger messages, the
interconnect is used for better bandwidth.
This option does not work with TCP, Elan, MX, or PSM.
-intra=nic Use the interconnect for all intra-host data transfers.
(Not recommended for high performance solutions.)
-intra=shm Use shared memory for all intra-host data transfers.
This is the default.
TCP interface selection
-netaddr This option is similar to -subnet, but allows finer
control of the selection process for TCP/IP connections.
MPI has two main sets of connections: those between
ranks and/or daemons where all the real message
traffic occurs, and connections between mpirun and the
daemons where little traffic occurs (but are still
necessary).
The -netaddr option can be used to specify a single
IP/mask to use for both of these purposes, or specify
them individually. The latter might be needed if
mpirun happens to be run on a remote machine that
doesn't have access to the same ethernet network as
the rest of the cluster. To specify both, the syntax would
be -netaddr IP-specification[/mask]. To specify
them individually it would be -netaddr
mpirun:spec,rank:spec. The string launch: can be
used in place of mpirun:.
The IP-specification can be a numeric IP address like
172.20.0.1 or it can be a hostname. If a hostname is
used, the value will be the first IP address returned by
gethostbyname(). The optional mask can be specified
as a dotted quad, or can be given as a number