lam-helpfile - LAM help message file
The lam-helpfile provides detailed error messages and suggestions for
help on how to fix common problems. In many places in LAM, when an
error occurs, this help file is consulted to display a detailed message
of what the error was and, when possible, suggestions on how to fix the
problem. It consists of much of the information from the LAM FAQ
(particularly in dealing with getting LAM up and running)
At present, the following LAM tools use this help file (it is expected
that more will use it in future releases. If you have suggestions for
locations where more detailed error messages would be helpful, please
let us know):
STRUCTURE AND SYNTAX
The help file is multiple blocks of help text separated by single line
delimiters. The delimiter lines are of the format:
Where programname is the general name of the program (or group of
programs) that this help message applies to, and topicname is the
specific topic that this message applies two.
The special keyword ALL can be used for either the programname or the
topicname in some cases; this is usually a "wildcard" value where
little specific information is available.
Within the block of the message, lines that begin with a "#" are
treated as comments; they are not printed out.
Three special escape sequences can be used within the help message:
%N Where N is a number from 1 to the number of arguments that the
help message is invoked with. The "%N" string is replaced with
the value of the Nth argument from the argument list. The
arguments are passed from the LAM binaries themselves; they
cannot be edited. The comments in the default LAM help file
explain how many arguments each message is invoked with, and
what each argument is.
Shows the result of the Unix perror(3) function.
Shows the result of the LAM terror() function, which is
essentially a wrapper around the Unix perror(3) function.
LOCATION OF HELP FILE
The exact location of the help file is configurable. This allows
system administrators and/or users to customize the help file for their
When LAM attempts to print an error message from the help file, it
looks for the help file in the following locations (in order):
Note the variable $LAMHELPDIR; this variable can be set according to
platform, for example, to provide operating system-specific
information, or information specific to particular groups of machines,
etc. It can also be set to provide help messages in different
$SYSCONFIDIR is typically $prefix/etc, where $prefix is the location to
where LAM was installed; it was the option supplied to ./configure when
LAM was built (or /usr/local/lam-7.1.2, by default). However, note
that the value of $SYSCONFDIR can be overridden when LAM is configured
with the --sysconfdir switch.
The following is an example customization of the help for the hboot and
lamboot programs, when the user supplies a host file name that is not
%1 could not open the hostfile "%2" for the following reason:
Things to check:
- ensure that the file exists
try "ls -l %2"
- ensure that you have read permissions on the file
try "cat %2"
You may not need to specify a host file at all; the system
administrators have defined the all of Beowulf cluster host names in
the LAM default host name list. If you wish to use all of the Beowulf
nodes, simply execute:
If you have any problems with LAM, please send mail to:
default LAM help file
hboot(1), lamboot(1), lamexec(1), lamhalt(1), lamnodes(1), lamwipe(1),
mpicc(1), mpiCC(1), mpif77(1), mpirun(1), recon(1), tkill(1), tping(1),