lamboot - Start a LAM multicomputer.

SYNTAX

       lamboot [-dhvxH] [<bhost>]

OPTIONS

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

       -h      Print the command help menu.

       -v      Be verbose.

       -x      Run in fault tolerant mode.

       -H      Do not display the command header.

DESCRIPTION

       The  lamboot  tool  starts the LAM software on each of the
       machines specified in the boot schema, <bhost>.  The  user
       may wish to first run the recon(1) tool to verify that LAM
       can be started.

       Starting LAM is a three  step  procedure.   In  the  first
       step,  hboot(1)  is  invoked  on  each  of  the  specified
       machines.  Then each machine allocates a dynamic port  and
       communicates  it  back to lamboot which collects them.  In
       the third step, lamboot gives each  machine  the  list  of
       machines/ports  in  order to form a fully connected topol­
       ogy.  If any machine was not able to start, or if a  time­
       out  period  expires before the first step completes, lam­
       boot invokes wipe(1) to  terminate  LAM  and  reports  the
       error.

       The  remote  shell program that is used to invoke commands
       on remote hosts is set when LAM is configured.  It is typ­
       ically  rsh, but can be set to any value by the person who
       setup/compiled LAM.  This program  can  be  overridden  at
       lamboot  invocation time by setting the LAMRSH environment
       variable to a suitable remote shell program.  For example:

              setenv LAMRSH "ssh -x"

       This will force LAM to use the "ssh" client to invoke pro­
       grams on remote nodes, and ensure that "ssh" uses  the  -x
       command  line  flag (to suppress the ssh 1.x client series
       standard information banner that is normally output to the
       standard error, which would cause lamboot to fail).

       The  <bhost> file is a LAM boot schema written in the host
       file syntax.  See bhost(5).  Instead of the command  line,
       a boot schema can be specified in the LAMBHOST environment
       variable.  Otherwise a default file, bhost.def,  is  used.

       In addition, lamboot uses a process schema for  the  indi­
       vidual  LAM  nodes.   A  process schema (see conf(5)) is a
       description of the processes which constitute the  operat­
       ing  system on a node.  In general, the system administra­
       tor maintains this file.  It is also possible for the user
       to  customize  the  LAM  software  with  a private process
       schema.

   Fault Tolerance
       If the -x option is given,  LAM  runs  in  fault  tolerant
       mode.   In  this  mode, nodes exchange ``heart beat'' mes­
       sages periodically to make sure all nodes are running  and
       the  links connecting them are operational.  When a node's
       heart beats stop, it is  declared  ``dead''  and  all  LAM
       nodes  (and processes) are notified.  This allows users to
       write fault tolerant applications that can degrade  grace­
       fully, or fully recover by replacing the defunct node with
       another (see lamgrow(1)).  Since this  mode  introduces  a
       performance penalty, it is not activated by default.

EXAMPLES

       lamboot -v
           Start  LAM  on  the  machines described in the default
           boot schema.  Report about important steps as they are
           done.

       lamboot mynodes
           Start LAM on the machines described in the boot schema
           mynodes.  Operate silently.

FILES

       $LAMHOME/boot/bhost.def default boot schema file

       $LAMHOME/boot/conf.lam default process schema file for LAM
                                         nodes

SEE ALSO

       recon(1),  wipe(1), bhost(5), hboot(1), conf(5), lam-help­
       file(5)