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System Management Guide: Operating System and Devices

Limitation of Resources

Resource Types

The following types of resources are supported:

CPU:

This resource is the percentage of available CPU time used by a process. This is the sum of the CPU time used by each thread in the process. (Note that for an MP system, the maximum available CPU time is the sum of that for each CPU individually.)

memory:

This resource is the percentage of available system physical memory used by a process.

Specifying Resource Limit Values

Resource limit values are specified in the resource limit file by resource type within stanzas for each class. The limits are specified as a minimum to maximum range separated by a hyphen (with whitespace ignored).

WLM Resource Limits File Format

The files are stored in a subdirectory of /etc/wlm that you create. For example, you can create a subdirectory named sample_config. Format the WLM resource limits file /etc/wlm/sample_config/limits as a standard AIX attribute stanza file with the class name as the stanza header followed by a colon and attribute-value pairs on separate lines following the class name. The attribute and values are separated by an equal sign (=).

The only whitespace that is significant in the resource limits file is the carriage return. Comment lines are preceded by an asterisk.

The resources CPU and memory are used as attributes with the percentage specified as an integral value from 0 to 100.

Future resource limits and other attributes can be added and still preserve backward compatibility with old WLM resource limitation files.

Example /etc/wlm/sample_config/limits File

Default:



	CPU = 0% - 100%

	memory = 0% - 100%



System:



	CPU = 10% - 100%

	memory = 20% - 100%



student:



	CPU = 10% - 100%

	memory = 20% - 100%


Specifying Target Shares

Create a subdirectory in the /etc/wlm directory, for example sample_config. Specify resource target share values in the /etc/wlm/sample_config/shares file by resource type within stanzas for each class. The target shares are specified by a number between 1 and 65535.

Example /etc/wlm/sample_config/shares File

Default:



	CPU = 20

	memory = 20



System:



	CPU = 20

	memory = 20



student:



	CPU = 10

	memory = 20



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