lam-helpfile - LAM help message file
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):
The help file is multiple blocks of help text separated by single line
delimiters. The delimiter lines are of the format:
is the general name of the program (or group of
programs) that this help message applies to, and topicname
specific topic that this message applies two.
The special keyword ALL
can be used for either the programname
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:
- 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.
The exact location of the help file is configurable. This allows system
administrators and/or users to customize the help file for their particular
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 languages.
is typically $prefix/etc
, where $prefix
location to where LAM was installed; it was the option supplied to ./configure
when LAM was built (or /usr/local/lam-7.1.4, by default). However, note that
the value of $SYSCONFDIR
can be overridden when LAM is configured with
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 found.
%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), perror(3)