NAME

       lamhalt - Shutdown the LAM/MPI run-time environment.

SYNOPSIS

       lamhalt [-dhHv]

OPTIONS

       -d          Turn on debugging mode.  This implies -v.

       -h          Print the command help menu.

       -i          Return immediately (even before the LAM universe is fully halted); deprecated

       -H          Suppress printing the header message.

       -v          Be verbose.

DESCRIPTION

       The  lamhalt  tool  terminates  the  LAM software on each of the nodes that were initially
       booted with lamboot and/or lamgrow.  No additional command line arguments are necessary  -
       lamhalt  simply  sends a message to each remote node telling it to shut down.  Each remote
       node invokes tkill(1) locally to shut down.  See tkill(1) for a description of how LAM  is
       terminated on each node.

       lamhalt  may fail if one of the remote nodes has failed, and does not respond to lamhalt's
       queries.  In this case, the lamwipe(1) command should be used to shut  down  LAM/MPI.   If
       lamwipe(1)  fails, the user can manually invoke tkill(1) on the troubled node.  In extreme
       cases, the user may have to terminate individual LAM processes with kill(1).

       Older versions of lamhalt would return 1-3 seconds before the entire LAM universe was shut
       down.   This  caused  problems for some LAM users, particularly those who had scripts that
       invoked lamboot immediately after lamhalt.  lamhalt has therefore  been  changed  to  wait
       until the entire LAM universe is down before exiting.  This makes the execution of lamhalt
       take a few seconds (typically less than 5).

       For users who want the old lamhalt behavior, use the -i  (or  "immediate")  switch,  which
       will  cause  lamhalt to return immediately, likely before the entire LAM universe has been
       taken down.

EXAMPLES

       lamhalt -d
           Shutdown LAM on the machines and be verbose about its actions.

SEE ALSO

       recon(1), lamboot(1), tkill(1), bhost(5), lam-helpfile(5), lamwipe(1)