cmx(8) System Manager's Manual cmx(8)
Name
cmx - generic communication exerciser
Syntax
/usr/field/cmx [ -h ] [ -ofile ] [ -tn ] -l line-1 ...
Description
The exerciser will write, read, and validate random data and packet lengths on a given communications line. The line under test must have
a loopback connector attached to the distribution panel or the cable and the line must be disabled in the file and a non-modem line. That
is, the flag must be set to off.
The exerciser runs until or kill -15 pid is sent to the process.
A logfile is made in for you to examine and then remove. If there are errors listed in the logfile, make sure that you check the file,
because that is where the driver and kernel error messages are saved.
You must specify the -l flag followed by the lines to test. The line-n arguments identify the lines to be tested. A maximum of 32 lines
can be tested at any one time. The line-n arguments are specified as names taken from the directory without the letters ``tty''. For
example, if the directory lists tty03, the line argument is 03.
The DEVICES section lists the devices that can be tested.
Restrictions
If there is a need to run a system exerciser over an NFS link or on a diskless system there are some restrictions. For exercisers that
need to write into a file system, such as the target file system must be writable by root. Also the directory, in which any of the exer-
cisers are executed, must be writable by root because temporary files are written into the current directory. These latter restrictions
are sometimes difficult to overcome because often NFS file systems are mounted in a way that prevents root from writing into them. Some of
the restrictions may be overcome by copying the exerciser to another directory and then executing it.
Options
-h Prints help message about this command.
-ofile Save output diagnostics in file.
-tn Run time in minutes (n). The default is to run until a or kill -15 pid is sent to the process.
Restrictions
Pseudo devices (those whose first character after tty is p, q, r, s, t, u) cannot be tested. Neither can lta devices with major #39.
Devices
Use the command on to find out which tty line corresponds to a device line number.
Examples
The following example runs the exerciser for 60 minutes on lines 00, 13, 22, and 32.
% /usr/field/cmx -t60 -l 00 13 22 32
The following example runs the exerciser on lines 11, 42, 45, and 76 in the background until interrupted by a or kill -15 pid.
% /usr/field/cmx -l 11 42 45 76 &
See Also
Guide to System Exercisers
cmx(8)
