tundefault Command

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The tundefault command is used to force all tuning parameters to be reset to their default value. The -p flag makes changes permanent, while the -r flag defers changes until the next reboot operation. The -K flag defers changes until the next Live Update operation.

The following is the syntax for the tundefault command:

tundefault [-p|-r [-K]]

The following example resets all tunable parameters to their default value, except the parameters of type Bosboot and Reboot, and parameters of type Incremental set at values bigger than their default value.

 tundefault

Error messages will be displayed for any parameter change that is not permitted.

The following example resets all the tunable parameters to their default value. It also updates the /etc/tunables/nextboot file, and if necessary, offers to run bosboot, and displays a message warning that rebooting is needed for all the changes to be effective.

tundefault -p

This command permanently resets all tunable parameters to their default values, returning the system to a consistent state and making sure the state is preserved after the next reboot.

The following example clears all the stanzas in the /etc/tunables/nextboot file, and proposes bosboot if necessary.

tundefault -r

When you use the -K flag with the -r flag as shown in the following example, the tundefault command resets all tunable parameters in the specified nextboot and nextliveupdate files to its default value. The -r flag clears the stanzas in the /etc/tunables/nextboot file, and prompts for a bosboot operation if necessary. The -K flag sets the tunable parameters in the /etc/tunables/nextliveupdate file to the default values if a non-default value was set.

tundefault -r -K