recon - Check if LAM can be started.

SYNTAX

       recon [-adhv] [<bhost>]

OPTIONS

       -a      Report all host errors.

       -d      Turn on debugging.

       -h      Print the command help menu.

       -v      Be verbose.

DESCRIPTION

       In  order  for LAM to be started on a remote UNIX machine,
       several requirements have to be fulfilled:

       1)     The machine must be reachable via the network.

       2)     The user must be able to remotely  execute  on  the
              machine  with the default remote shell program that
              was chosen when LAM was configured.  This  is  usu­
              ally  rsh(1),  but  any  remote  shell  program  is
              acceptable  (such  as  ssh(1),  etc.).   Note  that
              remote host permission must be configured such that
              the remote shell program will not ask for  a  pass­
              word when a command is invoked on remote host.

       3)     The  remote  user's  shell  must have a search path
              that will locate LAM executables.

       4)     The remote shell's startup file must not print any­
              thing  to  standard error when invoked non-interac­
              tively.

       If any of these requirements is not met  for  any  machine
       declared  in  <bhost>,  LAM will not be able to start.  By
       running recon first, the user  will  be  able  to  quickly
       identify  and  correct  problems  in  the setup that would
       inhibit LAM from starting.

       The local machine where recon is invoked must  be  one  of
       the machines specified in <bhost>.

       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.
       LAM  seaches  for <bhost> first in the local directory and
       then in the installation directory under boot/.

       variable.  The LAMRSH environment variable can be set with
       a  new  command  and  optional command line arguments. For
       example, the 1.x series of ssh clients require the -x flag
       to  be specified to suppress standard ssh information from
       being sent to the standard error (which would cause  recon
       to  fail).   For  example  (for  the  C shell and its der­
       rivates):

              setenv LAMRSH "ssh -x"

       recon tests each machine defined in <bhost> by  attempting
       to  execute on it the tkill(1) command using its "pretend"
       option (no action is taken).  This  test,  if  successful,
       indicates  that all the requirements listed above are met,
       and thus LAM can  be  started  on  the  machine.   If  the
       attempt  is  successful,  the next machine is checked.  In
       case the attempt fails, a  descriptive  error  message  is
       displayed and recon stops unless the -a option is used, in
       which  case  recon  continues   checking   the   remaining
       machines.

       If  recon  takes  a long time to finish successfully, this
       will be a good indication to the user that the LAM  system
       to  be  started  has  slow  communication links or heavily
       loaded machines, and it might be preferable to exclude  or
       replace some of the machines in the system.

FILES

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

EXAMPLES

       recon -v mynodes
           Check if LAM can be started on all the  UNIX  machines
           described  in  the  boot schema mynodes.  Report about
           important steps as they are done.

       recon -v -a
           Check if LAM can be started on all the  UNIX  machines
           described  in  the  default boot schema.  Report about
           important steps as  they  are  done.   Check  all  the
           machines; do not stop after the first error message.

SEE ALSO

       rsh(1), tkill(1), bhost(5), lamboot(1), wipe(1), lam-help­
       file(5)