tuncheck Command

The tuncheck command is used to validate a file.

The syntax of the tuncheck command is as follows:

tuncheck [-r [-K]|-p] -f filename

The following example validates the /etc/tunables/mytunable file for usage on current values.

tuncheck -f mytunable

The following example validates the /etc/tunables/nextboot file or my_nextboot file for usage during reboot. The -r flag is the only valid option when the file to check is the nextboot file.

tuncheck -r -f nextboot

tuncheck -r -f /home/bill/my_nextboot

The following example validates the /etc/tunables/nextliveupdate file or /home/bill/my_nextliveupdate file. The validated file is used during the reboot and Live Update operation. You must use the -r flag and the -K flag to check the nextliveupdate file.

tuncheck -r -K -f nextliveupdate

tuncheck -r -K -f /home/bill/my_nextliveupdate

All tunable parameters in the specified nextliveupdate or my_nextliveupdate file are checked for range, and dependencies, and if a problem is detected, a message similar to: Parameter X is out of range or Dependency problem between parameter A and B is issued. The -r and -p options control the values that are used in dependency checking for parameters that are not listed in the file and the handling of proposed changes to parameters of type Incremental, Bosboot, and Reboot. When you use the -K flag with the -r flag, the tuncheck command validates the file that contains the tunable parameter values. The validated file is used during the next boot and Live Update operations.

Except when used with the -r option, checking is performed on parameter of type Incremental to make sure that the value in the file is not less than the current value. If one or more parameters of type Bosboot are listed in the file with a different value than its current value, the user will either be prompted to run bosboot (when -r is used) or an error message will display.

Parameters having dependencies are checked for compatible values. When one or more parameters in a set of interdependent parameters is not listed in the file being checked, their values are assumed to either be set at their current value (when the tuncheck command is called without -p or -r), or their default value. This is because when called without -r, the file is validated to be applicable on the current values, while with -r, it is validated to be used during reboot when parameters not listed in the file will be left at their default value. Calling this command with -p is the same as calling it twice; once with no argument, and once with the -r flag. This checks whether a file can be used both immediately, and at reboot time.

Note: Users creating a file with an editor, or copying a file from another machine, must run the tuncheck command to validate their file.