raso Command

Purpose

Manages Reliability, Availability, Serviceability parameters.

Syntax

raso [-p | -r [-K]] [-y] [-o Tunable [= Newvalue] ]

raso [-p | -r [-K]] [-y] [-d Tunable]

raso [-p] [-r [-K]] [-y] -D

raso [-p] [-r | -K] [-F] -a

raso -h [Tunable]

raso [-F] [-K] -L [Tunable]

raso [-F] [-K] -x [Tunable]

Note: Multiple -o, -d, -x, and -L flags can be specified.

Description

Note: The raso command requires root authority.

The raso command is used to configure Reliability, Availability, Serviceability tuning parameters. The raso command sets or displays the current or next-boot values for all RAS tuning parameters. The raso command can also be used to make permanent changes or to defer changes until the next reboot. The specified flag determines whether the raso command sets or displays a parameter. The -o flag can be used to display the current value of a parameter or to set a new value for a parameter.

Understanding the Effect of Changing Tunable Parameters: Misuse of the raso command can cause performance degradation or operating system failure. Before modifying any tunable parameter, first read about all of the characteristics of the parameters in the Tunable Parameters section to fully understand the parameter's purpose. Then ensure that the Diagnosis and Tuning sections for this parameter apply to your situation and that changing the value of this parameter could help improve the performance of your system. If the Diagnosis and Tuning sections both contain only N/A, it is recommended that you do not change the parameter unless you are directed to do so by AIX development.

Flags

Table 1. Flags
Item	Description
-a	Displays current value, reboot value (when used with the -r option), Live Update value (when used with the -K option), or permanent values for all tunable parameters (when used with the -p option), one per line in pairs `Tunable = Value`. For the permanent option, a value is only displayed for a parameter if its reboot and current values are equal. Otherwise, NONE is displayed as the value.
-d `Tunable`	Resets the `Tunable` parameters to its default value. If a `Tunable` parameter, which must be changed because it is not set to its default value, meets one or more of the following sets of criteria, a warning message is displayed and no change is made to the parameter: The tunable parameter is of type Bosboot or Reboot. The tunable parameter is of type Incremental and was changed from its default value, and the -r flag is not used in combination. The tunable parameter is of type Reboot and is supported across the Live Update operation.
-D	Resets all `Tunable` parameters to their default values. If `Tunables` that need to be changed because they are not set to their default values meet one or more of the following sets of criteria, a warning message is displayed and no change is made: The tunable is of type Bosboot or Reboot. The tunable is of type Incremental and was changed from its default value, and -r is not used in combination. The tunable parameter is of type Reboot and is supported across the Live Update operation.
-F	Forces restricted tunable parameters to be displayed when the options -a, -L, or -x are specified alone on the command line. If you do not specify the -F flag, restricted tunables are not included, unless they are named in association with a display option.
-h `Tunable`	Displays help about the raso command if no `Tunable` parameter is specified. Displays help about the `Tunable` parameter if a `Tunable` parameter is specified.
-K	Sets the tunable parameter value in both /etc/tunables/nextboot and /etc/tunables/nextliveupdate files. The -K flag can be used only with the -r flag. When you specify the -K flag with the -r and -d (or -D) flags, the tunable parameter value is set to its default value in the /etc/tunables/nextboot and /etc/tunables/nextliveupdate files to be used during the next boot or Live Update operations. When you specify the -K flag with the -L or -x flag, the raso command displays the Live Update values.
-L `Tunable`	Lists the characteristics of one or all tunable parameters, with one tunable displayed per line by using the following format. If you specify the -K flag with the -L flag, the Live Update values are also displayed. NAME CUR DEF BOOT MIN MAX UNIT TYPE DEPENDENCIES -------------------------------------------------------------------- mtrc_commonbufsize 3974 3974 3974 1 5067 4KBpages D mtrc_enabled -------------------------------------------------------------------- mtrc_enabled 1 1 1 0 1 boolean B -------------------------------------------------------------------- mtrc_rarebufsize 2649 2649 2649 1 3378 4KB pages D -------------------------------------------------------------------- ... where: CUR = current value DEF = default value BOOT = boot value MIN = minimal value MAX = maximum value UNIT = tunable unit of measure TYPE = parameter type: D (for Dynamic), S (for Static), R (for Reboot),B (for Bosboot), M (for Mount), I (for Incremental), C (for Connect), and d (for Deprecated) DEPENDENCIES = list of dependent tunable parameters, one per line
-o `Tunable` [ =`Newvalue` ]	Displays or sets the value of a tunable parameter to a new value. The /etc/tunables/usermodified file is updated with the new tunable parameter value whenever you use the -o flag to change the value of a dynamic tunable. If a tunable parameter that you want to change meets one or more of the following sets of criteria, a warning message is displayed and no change is made to the parameter: The tunable parameter is of type Bosboot or Reboot. The tunable parameter is of type Incremental, and its current value is greater than the specified value, and the -r flag is not used in combination. The tunable parameter is of type Reboot, and the tunable parameter is supported across the Live Update operation. When you specify the -r flag with the -o flag without specifying a new value, the next boot value for tunable is displayed. When you specify the -K flag with the -o flag without specifying a new value, the value of the tunable parameter of type Live Update in the nextliveupdate file is displayed. When you specify the -p flag with the -o flag without specifying a new value, a value is displayed only if the current and next boot values for the tunable are the same. Otherwise, `NONE` is displayed as the value.
-p	When the -p flag is used with the -o, -d, or -D flag, changes apply to both the current and reboot values (in addition to the current value being updated, the /etc/tunables/nextboot file is updated). These combinations cannot be used on Reboot and Bosboot type parameters because the current values for these parameters cannot be changed. When the -p flag is used with the -a or -o flag without specifying a new value, values are displayed only if the current and next boot values for a parameter are the same. Otherwise, NONE is displayed as the value.
-r	When the -r flag is used with the -o, -d, or -D flag, changes apply to reboot values (the /etc/tunables/nextboot file is updated). If any parameter of type Bosboot is changed, you are prompted to run the bosboot command. When used with the -a or the -o flags without specifying a new value, next boot values for tunable parameters are displayed instead of current values. When used with the -K flag, changes apply to both the /etc/tunables/nextboot and /etc/tunables/nextliveupdate files.
-x `Tunable`	Lists the characteristics of one or all tunable parameters, with one tunable displayed per line by using the following format (spreadsheet format). If you specify the -K flag with the -x flag, the Live Update values are also displayed. `Tunable Current Default Reboot Minimum Maximum Unit Type Dependencies` Where `Tunable` is the tunable parameter, `Current` is the current value of the tunable parameter, `Default` is the default value of the tunable parameter, `Reboot` is the reboot value of the tunable parameter, `Minimum` is the minimum value of the tunable parameter, `Maximum` is the maximum value of the tunable parameter, `Unit` is the tunable unit of measure, `Type` is the parameter type, and `Dependencies` is the list of dependent tunable parameters. If you make any change (with -o, -d, or -D) to a parameter of type Mount, it results in a warning message that the change is only effective for future mountings. If you make any change (with -o, -d or -D) to a parameter of type Connect, it results in inetd being restarted, and a warning message that the change is only effective for future socket connections. If you make any change (with -o, -d, or -D) to a parameter of type Bosboot or Reboot without -r, it results in an error message. If you make any change (with -o, -d, or -D but without -r) to the current value of a parameter of type Incremental with a new value smaller than the current value, it results in an error message.
-y	Suppresses the confirmation prompt before running the bosboot command.

If you make any change (with -o, -d or -D) to a restricted tunable parameter, it results in a warning message that a tunable parameter of the restricted-use type has been modified. If you also specify the -r or -p options on the command line, you are prompted for confirmation of the change. In addition, at system reboot, the presence of restricted tunables in the /etc/tunables/nextboot file, which were modified to a value that is different from their default value (by using a command line that specifies the -r or -p options), results in an error log entry that identifies the list of these modified tunables.

You can specify a modified tunable value by using the abbreviations K, M, G, T, P, and E to indicate units. The following table shows the prefixes and values that are associated with the number abbreviations.

Table 2. Prefixes and values that are associated with the number abbreviations.
Abbreviation	Prefix	Power of 2
K	Kilo	2¹⁰
M	Mega	2²⁰
G	Giga	2³⁰
T	Tera	2⁴⁰
P	Peta	2⁵⁰
E	Exa	2⁶⁰

Thus, a tunable value of 1024 might be specified as 1 K.

Tunable Parameters type

All the tunable parameters that are manipulated by the tuning commands ( no, nfso, vmo, ioo, schedo, and raso) are classified into these categories:

Item	Description
Dynamic	If the parameter can be changed at any time
Static	If the parameter can never be changed
Reboot	If the parameter can be changed only during reboot
Bosboot	If the parameter can be changed only by running bosboot and rebooting the machine
Mount	If changes to the parameter are only effective for future file systems or directory mounts
Incremental	If the parameter can be incremented, except at boot time
Connect	If changes to the parameter are only effective for future socket connections. The parameters must be of type Bosboot.

For parameters of type Bosboot, whenever a change is performed, the tuning commands automatically prompt the user to ask if they want to execute the bosboot command. For parameters of type Connect, the tuning commands automatically restart the inetd daemon.

The current set of parameters that are managed by the schedo command includes only Dynamic and Reboot types.

Compatibility Mode

When running the raso command in the pre 5.2 compatibility mode that is controlled by the pre520tune attribute of sys 0, the reboot values for parameters, except for those of type Bosboot, are not considered because in this mode they are not applied at the boot time. For more information, see NFS tuning on the client in the Performance management guide.

In pre 5.2 compatibility mode, setting reboot values to tuning parameters remains achieved by embedding calls to tuning commands in scripts called during the boot sequence. Therefore, the parameters of type Reboot can be set without the -r flag so that existing scripts continue to work.

This mode is automatically turned on when a machine is MIGRATED to AIX 5.2. For complete installations, it is turned OFF and the reboot values for parameters are set by applying the content of the /etc/tunables/nextboot file during the reboot sequence. Only in that mode the -r and -p flags are fully functional. For more information, see Kernel Tuning in the Performance Tools Guide and Reference.

Tunable Parameters

For default values and range of values for tunables, refer the raso command help (-h <tunable_parameter_name>).

Table 3. Tunable parameters
Item	Description
kern_heap_noexec	Purpose Specifies whether no-execute protection must be enabled for the kernel heap. Tuning With protection enabled, any attempt to execute code in the protected heap results in a kernel exception.
kernel_noexec	Purpose Specifies whether no-execute protection must be enabled for kernel data regions. Tuning With protection enabled, any attempt to execute code in the protected regions result in a kernel exception.
llu_mode	Purpose Specifies whether the live library update (LLU) function must be enabled. Tuning The following values are the valid values for the llu_mode tunable parameter: 0: Specifies that the LLU function is disabled for all the processes regardless of the LLU program attributes. 1: Specifies that the LLU function is enabled for processes on which the LLU program attributes are enabled. This value is the default value for llu_mode tunable parameter. 2: Specifies that the LLU function is disabled for all the processes unless explicitly enabled with the `LDR_CNTRL` environment variable For more information, see Live Library Update (LLU).
mbuf_heap_noexec	Purpose Specifies whether no-execute protection must be enabled for the mbuf heap. Tuning With protection enabled, any attempt to execute code in the protected heap results in a kernel exception.
mtrc_commonbufsize	Purpose Specifies the memory trace buffer size for common events of Lightweight Memory Trace (LMT) which provides system trace information for First Failure Data Capture (FFDC). Tuning The default value is based on data generation under a reference system-wide activity, hardware, and system characteristics. The higher limit of the range is based on the hardware and system characteristics and depends on the current value of mtrc_rarebufsize because they share the LMT resource. Recorded events are saved in a system dump, or reported through user commands, or both.
mtrc_enabled	Purpose Defines the Lightweight Memory Trace (LMT) state. Tuning A value of 1 means LMT is enabled. To be effective, any change of state requires a subsequent bosboot and system reboot.
mtrc_rarebufsize	Purpose Specifies the memory trace buffer size for rare events of Lightweight Memory Trace (LMT) which provides system trace information for First Failure Data Capture (FFDC). Tuning The default value is based on data generation under a reference system-wide activity, hardware, and system characteristics. The higher limit of the range is based on the hardware and system characteristics and depends on the current value of mtrace_commonbufsize because they share the LMT resource. Recorded events are saved in a system dump, or reported through user commands, or both.
tprof_cyc_mult	Purpose Specifies the Performance Monitor PM_CYC and software event sampling frequency multiplier as a means to control the trace sampling frequency.
tprof_evt_mult	Purpose Specifies the Performance Monitor PM_* event sampling frequency multiplier as a means to control the trace sampling frequency.
tprof_inst_threshold	Purpose Specifies the minimum number of completed instructions between Performance Monitor event samples as a means to control the trace sampling frequency. Values The default value is 1000. The range is 1 to 2G-1. The type is Dynamic. Diagnosis Not applicable Tuning Not applicable
tprof_evt_system	Purpose Allows or restricts the nonprivileged users from using the system-wide Performance Monitor event-sampling. Values The default is 0. The range is 0 - 1. The type is Dynamic. The unit is Boolean. Tuning With tprof_evt_system enabled (value 1), the nonprivileged users can use tprof and pmctl commands to perform system-wide Performance Monitor event-sampling. When disabled (value 0), nonprivileged users can perform event-sampling for processes that are started with -y option of tprof and pmctl commands. In the disabled mode, nonprivileged users cannot perform event-sampling of kernel and kernel extensions.

Security

Attention RBAC users: This command can perform privileged operations. Only privileged users can run privileged operations. For more information about authorizations and privileges, see Privileged Command Database in Security. For a list of privileges and the authorizations that are associated with this command, see the lssecattr command or the getcmdattr subcommand.

Examples

To list the current and reboot value, range, unit, type, and dependencies of all tunable parameters that are managed by the raso command, enter the following command:
```
raso -L
```
To turn off the Lightweight Memory Trace, enter the following command:
```
raso -r -o mtrc_enabled=0
```
To display help for mtrc_commonbufsize, enter the following command:
```
raso -h mtrc_commonbufsize
```
To set tprof_inst_threshold to 10000 after the next reboot, enter the following command:
```
raso -r -o tprof_inst_threshold=10000
```
To permanently reset all raso tunable parameters to their default values, enter the following command:
```
raso -p -D
```
To list the reboot level for all Virtual Memory Manager tuning parameters, enter the following command:
```
raso -r -a
```