tundefault Command
Purpose
Reset all tunable parameters to their default value.
Syntax
Description
The tundefault command launches all the tuning commands (ioo, vmo, schedo, no, nfso, and raso) with the -D flag. This resets all the AIX® tunable parameters to their default value, except for parameters of type Bosboot and Reboot, and parameters of type Incremental set at values bigger than their default value, unless -r was specified. Error messages are displayed for any parameter change impossible to make.
Flags
Item | Description |
---|---|
-p | Makes the changes permanent: resets all the tunable parameters to their default values and updates the /etc/tunables/nextboot file. |
-r | Defers the reset to their default value to next reboot. This clears stanza(s) in the /etc/tunables/nextboot file, and if necessary, proposes bosboot and warns that a reboot is needed |
Tunable Parameter Types
Item | Description |
---|---|
Dynamic | Can be changed at any time. |
Static | Can never be changed |
Reboot | Can only be changed during the reboot sequence |
Bosboot | Can only be changed by running bosboot and rebooting the machine |
Mount | Changes made are only effective for future filesystems or directory mountings |
Incremental | Can only be incremented, except at boot time. |
Connect | Changes are only effective for future socket connections. |
Examples
- To permanently reset all tunable parameters to their default values,
enter:
tundefault -p
All of the tuning commands are launched with the -Dp flags. This resets all the tunable parameters to their default value. This also updates the /etc/tunables/nextboot file. This command completely and permanently resets all tunable parameters to their default values.
- To defer the setting of all tunable parameters until next reboot,
enter:
Calls all tuning commands with -Dr. This clears all of the stanzas in the /etc/tunables/nextboot file, and if necessary, proposes bosboot and displays a message warning that a reboot is necessary to make the changes effective.tundefault -r
Files
Item | Description |
---|---|
/usr/sbin/tundefault | Contains the tundefault command. |
/etc/tunables/ | Contains all the tunable files. |