chdev(1M) — ADMINISTRATOR COMMANDS
NAME
chdev − change the values of system tunable parameters
SYNOPSIS
/usr/sbin/chdev −P −l module −a parameter [-q]
/usr/sbin/chdev −h
DESCRIPTION
chdev modifies the current value of a system tunable parameter within a particular module. The change is made to the module’s master file. A copy of the original file is saved in the OLD directory in /etc/master.d. Only one copy is maintained; i.e., each time you change the master file, a copy of the original file is written over the previously-saved copy (if it exists).
The following are the arguments to chdev.
-P is a mandatory argument reserved for future compatibility.
-l module
identifies the module whose parameters are to be modified.
-a parameter
assigns value(s) to one or more parameter(s). parameter can be a number or a string.
If parameter is a string, it must be enclosed in double quote marks, and the entire expression must be enclosed in single quote marks to prevent shell evaluation of the string inside the double quote marks.
You can assign multiple parameter values with a single -a option. When you do so, you must enclose the parameter values in single quote marks. Alternatively, you can use multiple -a options to set multiple parameter values.
-q suppresses the display of the command output message when the command has successfully completed execution. This option has no effect on error messages.
-h displays the command usage message.
EXAMPLE
To modify the value of the NPROC parameter in the kernel module, enter the following:
chdev -P -l kernel -a ’NPROC=1000’
The system will display a message similar to the following:
kernel changed
NOTE
When you modify parameters with chdev, the new values do not take effect until you build a new kernel using buildsys and then reboot the system.
chdev does not do type checking. If you specify a string for the value of a parameter that previously contained a decimal value, chdev does not identify this as an error.
chdev does not enforce the range or the tunable flag information displayed by lsattr.