Commands Reference, Volume 6

wlmcntrl Command

Syntax

wlmcntrl [ [ -a | -p ] [ -g ] [ -d Config_Dir ] [ -o | -q ]

wlmcntrl -u [ -S Superclass | -d Config_Dir ]

The wlmcntrl command stops, starts, updates or queries the state of Workload Manager (WLM). When starting or updating WLM, the WLM property files for the target configuration are pre-processed, and the data is loaded into the kernel. WLM can be started in two different modes:

An active mode where WLM monitors and regulates the CPU, memory and disk I/O utilization of the processes in the various classes.
A passive mode where WLM only monitors the resource utilization without interfering with the standard operating system resource allocation mechanisms.

The active mode is the normal operating mode of WLM.

The classes, their limits and shares are described respectively in the classes, limits, and shares files. The automatic assignment rules are taken from the rules file. The class properties files for the superclasses of the WLM configuration Config are located in the subdirectory /etc/wlm/Config. The class properties files for the subclasses of the superclass Super of the configuration Config are located in /etc/wlm/Config/Super. The standard configuration shipped with the operating system is in /etc/wlm/standard. The current configuration is the one in the directory pointed to by the symbolic link /etc/wlm/current.

When the -d Config_dir flag is not used, wlmcntrl uses the configuration files in the directory pointed to by the symbolic link /etc/wlm/current.

When the -d Config_dir flag is used, wlmcntrl uses the configuration files in /etc/wlm/Config_dir and updates the /etc/wlm/current symbolic link to point to /etc/wlm/Config_dir, making /etc/wlm/Config_dir the current configuration. This is the recommended way to make /etc/wlm/Config_dir the current configuration.

When updating WLM using the -u flag, an empty string can be passed as Config_dir with the -d flag:

     wlmcntrl -u -d ""

will simply refresh (reload) the assignment rules of the current configuration into the kernel without reloading the class definitions. This can be useful when a prior activation of WLM detected that some application files could not be accessed. Once the system sdministrator has fixed the problems with either the rules or the files, this command can be used to reload only the rules.

Flags

-a	Starts WLM in active mode or switches from passive to active mode. This is the default when no flag other than -d is specified.
-d Config_dir	Uses /etc/wlm/Config_dir as an alternate directory for the classes, limits, shares and rules files, and makes /etc/wlm/Config_dir the current configuration. This flag is effective when starting the WLM in active or passive mode, or when updating the WLM. This flag cannot be used in conjunction with the -o and -q flags or when switching from active to passive mode or vice versa.
-g	Instructs WLM to ignore any potential resource set bindings. This means that all classes have access to the whole resource set of the system, regardless of whether or not they use a restricted resource set.
-o	Stops Workload Manager.
-p	Start WLM in passive mode or switches from active to passive mode.
-q	Queries the current state of WLM. Returns: 0 WLM is running in active mode. 1 WLM is not started. 2 WLM is running in passive mode. 3 WLM is running in active mode with no rset bindings. 4 WLM is running in passive mode with no rset bindings. A message indicating the current state of WLM is printed on STDOUT.
-S Superclass	Requests an update of WLM that is limited to the subclasses of the superclass, use this flag with the -u flag.
-u	Updates the WLM. A single update operation can change the attributes, limits and shares of existing classes and/or add or remove classes. Update can be used by a user with root authority to switch to an alternate configuration. Update can also be used by a subclass administrator to update only the subclasses of the superclass he has administrative access to (-S flag).

Security

Access Control: Starting, stopping, switching from active to passive mode (or vice-versa) and updating superclasses requires root privileges. Updating the subclasses of a given superclass requires only adminuser or admingroup privileges (subclass administrator). Any user can query the state of WLM.

Files

classes	Contains the names and definitions of the classes.
limits	Contains the resource limits enforced on the classes.
rules	Contains the automatic assignment rules.
shares	Contains the resource shares allocated to the classes.
description	Contains the description text for each configuration.

Related Information

The chclass command, lsclass command, mkclass command, and rmclass command.