lamhalt - Shutdown the LAM/MPI run-time environment.
lamhalt [-dhHv]
- -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.
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.
- lamhalt -d
- Shutdown LAM on the machines and be verbose about its
actions.
recon(1),
lamboot(1),
tkill(1),
bhost(5),
lam-helpfile(5),
lamwipe(1)