tuncheck Command

Purpose

Validates the file that contains the tunable parameters.

Syntax

tuncheck [ -r [-K] | -p ] -f Filename

Description

The tuncheck command validates the file that contains the tunable parameters. All tunable parameters listed in the specified file are checked for range and dependencies. If a problem is detected, a warning is issued.

The tuncheck command validates the following items:

Validation against the current context: Checks whether the tunable parameters in the specified file can be applied immediately. Tunable parameters that are not listed in Filename are interpreted as current values. The checking fails if a tunable of type Incremental is listed with a smaller value than its current value; it also fails if a tunable of type Bosboot or Reboot is listed with a different value than its current value.
Validation against the next boot context: Checks whether the tunable parameters in the specified file can be applied during a reboot, that is, if it could be a valid nextboot file. The file validation does not fail if a tunable parameter of type Incremental is specified with a smaller value than its current value. If a tunable of type Bosboot or Reboot is listed with a different value than its current value, a warning is issued but the checking does not fail.
Validation against the next Live Update context: Checks whether the tunable parameters in the specified file can be applied during the Live Update operation, that is, whether the file can be a valid nextliveupdate file. The validation does not fail if a tunable parameter of type Incremental is specified with a smaller value than its current value. If a tunable parameter of type Bosboot or Reboot is listed with a different value than its current value in the specified file, a warning message is displayed but the file validation does not fail.

Additionally, warnings are issued if Filename contains unknown stanzas, or unknown tunables in a known stanza. However, that does not make the checking fail.

Upon success, the AIX_level, Kernel_type and Last_validation fields in the info stanza of the checked file are updated.

Flags

Item	Description
-f Filename	Specifies the name of the tunable file to be checked. If it does not contain the '/' (forward slash) character, the name is relative to /etc/tunables.
-K	Checks the specified file in a boot and Live Update context.
-p	Checks Filename in both current and boot contexts. This is equivalent to running tuncheck twice, one time without any flag and one time with the -r flag.
-r	Checks Filename in a boot context.

If -p or -r are not specified, Filename is checked according to the current context.

Tuning 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.

Exit Status

0: Filename is valid.
>0: Filename is invalid, message have been provided.

Examples

To check whether mytunable can be applied immediately, type:
```
 tuncheck -f ./mytunable
```
To check whether /etc/tunables/nextboot can be applied during a reboot, type:
```
 tuncheck -r -f nextboot 
```
To check whether /etc/tunables/nextboot can be applied immediately and after a reboot, type:
```
tuncheck -p -f nextboot
```
To check whether the tunable parameters in the mytunables file can be applied during a reboot and Live Update operation, enter the following command:
```
tuncheck -r -K -f ./mytunable
```

Files

Item	Description
/usr/sbin/tuncheck	Contains the tuncheck command.
/etc/tunables	Contains all the tunable files.