Change the attributes and resource entitlements of a Workload Management class.
chclass -a Attribute=Value {[-a Attribute=Value]...} [ -c | -m | -b KeyWord=Value] [ -d Config_Dir] [ -S SuperClass] Name
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, -m for memory, and -b for disk I/O throughput, with the keyword value in min, softmax, hardmax or shares.
Note: Only the root user can change the attributes of a superclass. Only root or authorized users whose user ID or group ID matches the user name or group name specified in the attributes adminuser and admingroup of a superclass can change the attributes of a subclass of this superclass.
Normally, chclass updates the attributes of a class in the relevant WLM property files, and the modifications are applied to the in-core class definition (active classes) only after an update of WLM using the wlmcntrl command.
If an empty string is passed as the configuration name (Config_dir) with the -d flag, the change applies only to the in-core class attributes, and no property file is updated, making the changes temporary (the change is lost if WLM is stopped and restarted or the system is rebooted).
The following attributes can be changed:
| tier | Specifies the tier value. 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). |
| inheritance | If inheritance is set to yes, the children of processes in this class remain in the class upon exec regardless of the automatic assignment rules in effect. If inheritance is set to no, the assignment rules apply normally. The default if not specified is no. |
| localshm | Indicates whether memory segments accessed by processes in different classes remain local to the class they were initially assigned to or if they go to the Shared class. The possible value is Yes or No. If not specified, the default is No. |
| authuser | Specifies the user name of the user allowed to assign processes to this class. The default when the attribute is not specified is root. |
| authgroup | Specifies the group name of the group of users allowed to assign processes to this class. There is no default value. |
| rset | Specifies the name of a resource set the processes in the class have access to. The default is that the class has access to all the resources on the system. |
| adminuser | Specifies the user name of the user allowed to administer the subclasses of this superclass. This attribute is valid only for superclasses. The default, when the attribute is not specified is a null string, and, in this case, only root can administer the subclasses. |
| admingroup | Specifies the group name of the group of users allowed to administer the subclasses of this superclass. This attribute is valid only for superclasses. The default value, when the attribute is not specified is a null string, meaning that no group can administer the subclasses. |
Note: The default values for a class can be read using lsclass -D and can be changed by manually editing the property files classes, shares, or limits to add a default stanza. See the description of these files in the AIX 5L Version 5.1 Files Reference for details.
| description | The class description text can be composed of any ASCII character, except colon (:) and comma (,). |
| classes | Contains the names and definitions of the classes. |
| limits | Contains the resource limits enforced on the classes. |
| shares | Contains the resource shares attributes for each class. |
The wlmcntrl command, lsclass command, mkclass command, and rmclass command.