chclass Command

Commands Reference, Volume 1

chclass Command

Purpose

Change a Workload Management class and its limits.

Syntax

chclass -a Attribute=Value {[-a Attribute=Value]...} [-c|-m <keywd>=<value>] [-d Config_dir] Name

Description

The chclass command changes attributes for the class identified by the Name parameter. The class must already exist. To change an attribute, specify the attribute name and the new value with the Attribute=Value parameter. To change a limit or shares value, use option -c for cpu and -m for memory, with the keyword value in min, max or shares.

Attributes

The following attributes can be changed:

Class properties:

tier

The tier value for a class is the position of the class in the hierarchy of resource limitation desirability for all classes. A class with a lower tier value will be more favored. The tier value is a number from 0 to 9 (default is 0).

Class limits and shares, for CPU or memory resource:

min	Minimum percentage of the resource (CPU time or memory pages) that must be made available when requested, expressed as a percentage of the total resource available in the system. Possible values range from 0 to 100 (default is 0).
shares	Maximum ratio of the resource that can be made available if there is contention. This parameter is expressed in shares of the total resource available in the system. The actual ratio of the resource is dynamically computed, proportionally to the shares of all active classes. If a class has no running process, its shares are excluded from the computation. The shares are arbitrary numbers from 1 to 65535 (default is 1).
max	Maximum percentage of the resource that can be made available, even if there is no contention. Possible values range from 1 to 100 (default is 100). Specifying a value different from the default 100 for memory can result in some memory pages remaining unused, while some processes in the class could use more.

Class description:

description

The class description text can be composed of any ASCII character, except colon (":").

Flags

-d Config_dir

Use /etc/wlm/Config_dir as alternate directory for the properties files. If this flag is not present, the current configuration files in the directory pointed to by /etc/wlm/current are used.

Files

/etc/wlm/current/classes	Contains the names and definitions of the classes for the current workload management configuration.
/etc/wlm/current/limits	Contains the resource limits enforced on the classes for the current workload management configuration.
/etc/wlm/current/shares	Contains the resource shares attributes for each class of the current workload management configuration.
/etc/wlm/current/description	Contains the class description text for each class of the current workload management configuration.

Related Information

The wlmcntrl, lsclass, mkclass, and rmclass commands.