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.

The following is the syntax for the tundefault command:

tundefault [-p|-r]

For example, 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.

For example, 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.

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

tundefault -r