tunchange Command

Purpose

Updates one or more tunable stanzas in a file.

tunchange -f Filename ( -t Stanza ( {-o Parameter[=Value]} | -D ) | -m Filename2 )

The tunchange command unconditionally updates a tunable file. It can also merge a second file with the current file.

Note: No message will be displayed (even when a parameter of type bosboot is changed).

Item	Description
-f Filename	Name of the updated tunable file. If the name does not include the '/' (forward slash) character, it is considered to be relative to /etc/tunables.
-t Stanza	Name of the stanza to update. Stanza is either schedo, vmo, ioo, no, nfso, or raso. Stanza corresponds to the name of the command which can update the parameter or parameters specified by the -o flag.
-o Parameter=Value	Parameter to be set to Value. It must be valid in the Stanza specified by the -t flag and consistent with the other parameters of the file specified by the -f flag.
-D	Resets all parameters of the Stanza to their default value.
-m Filename2	Merges the Filename2 file with the current Filename file.

Item	Description
0	Changes were correctly applied.
>0	One of the following conditions caused an error: The specified Filename, Filename2, or Stanza was invalid. Parameter=Value was invalid for the Parameter. No message was provided.

To update the pacefork parameter in the /etc/tunables/nextboot file, type:
```
tunchange -f nextboot -t schedo -o pacefork=10
```
To update the pacefork parameter in the /home/mine/mytunable file, type:
```
tunchange -f /home/mine/mytunable -t schedo -o pacefork=10
```
To reset all schedo stanza parameters to their default value in the /etc/tunables/nextboot file, type:
```
tunchange -f nextboot -t schedo -D
```
To merge the /home/mine/mytunable file with the /etc/tunables/nextboot file, type:
```
tunchange -f nextboot -m /home/mine/mytunable
```

Item	Description
/usr/sbin/tunchange	Contains the tunchange command.
/etc/tunables/	Contains the default tunable files.