Kernel tuning
You can make permanent kernel-tuning changes without having to edit any rc files. This is achieved by centralizing the reboot values for all tunable parameters in the /etc/tunables/nextboot stanza file. When a system is rebooted, the values in the /etc/tunables/nextboot file are automatically applied.
- The tunchange command is used to change values in a stanza file.
- The tunsave command is used to save values to a stanza file.
- The tunrestore is used to apply a file; that is, to change all tunables parameter values to those listed in a file.
- The tuncheck command must be used to validate a file created manually.
- The tundefault is available to reset tunable parameters to their default values.
All six tuning commands (no, nfso, vmo, ioo, raso, and schedo) use a common syntax and are available to directly manipulate the tunable parameter values. Available options include making permanent changes and displaying detailed help on each of the parameters that the command manages. A large majority of tunable parameter values are not modifiable when the login session is initiated outside of the global WPAR partition. Attempts to modify such a read only tunable parameter value is refused by the command and a diagnostic message written to standard error output.
SMIT panel is also available to manipulate the current and reboot values for all tuning parameters, as well as the files in the /etc/tunables directory.