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)

LAM 7.1.4                                          July, 2007                                         LAMHALT(1)