Content-type: text/html Man page of class_admin

class_admin

Section: Maintenance Commands (8)
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NAME

class_admin - Administer class scheduling and the database.  

SYNOPSIS

/usr/sbin/class_admin [subcommand]  

DESCRIPTION

The class_admin command is used to configure and control the class scheduler and to maintain its database /etc/class.

The class_admin command can be run interactively or non-interactively.

Non-interactive mode is useful when you would like to execute a single class_admin subcommand without user interaction. This allows class_admin to be run from within a script, which makes it easy to enable class scheduling at system startup through use of an init(8) script. To run class_admin non-interactively, specify a single class_admin subcommand as an argument when invoking class_admin.

Interactive mode is useful when you would like to execute several class_admin subcommands. To run class_admin interactively, invoke class_admin without specifying a subcommand argument.

Should the class scheduler database not exist, class_admin will automatically create one when it starts up. If the command is invoked non-interactively, a default database is created (using the following interactive defaults). The interactive process will require you to answer three questions: Shall processes that have not been explicitly assigned to a defined class be assigned to a "default" class? Enter (y/n) [n]:

To be class scheduled, a process must be assigned to a class. If you answer <y> to this prompt, a special class called the "default" class will be created, and any process that has not been explicitly assigned to one of the defined classes will be assigned to this class. If you answer <n> to this prompt, then only those processes which have been explicitly assigned to a defined class will be class scheduled. Enforce class scheduling when the CPU is otherwise idle? (y/n) [n]:

The administrator has the option of allowing classes to exceed their CPU percentage when the system is otherwise idle if yes is answered. Otherwise, classes are held to their allotted percentage even if the CPU has no other work. How often do you want the system to reset class usage? Enter number of seconds (2):

Use a small number (several seconds) if there are interactive jobs subject to class scheduling to give them a quick response time. If only batch jobs are class scheduled, response time is not an issue and larger values may be used.

If class scheduling is enabled, changes made take effect immediately.

Subcommands

Add a group or user to an existing class. If the group or user exists in another class, you will be asked if you want to move it or not. More than one group or user may be specified.

syntax: add <class name> <type> <id ... ...>
        <type> = 'gid' | 'uid' | 'session' | 'pgrp' | 'pid'

Change the CPU percentage allotted to a class. The system will not allow the total of all classes to exceed 100%.

syntax: change <class name> <cpu %>

Create a new class. The name must be unique. The newly created class will be empty. Use the 'add' command to populate the class.

syntax: create <class name> <cpu %>

Set up the basic class scheduling parameters. You will be prompted for each parameter.

syntax: configure

Remove a group or user from an existing class. More than one group or user may be specified.

syntax: delete <class name> <type> <id ... ...>
        <type> = 'gid' | 'uid' | 'session' | 'pgrp' | 'pid'

Destroy an existing class. If the class is not empty, you will be asked if it's OK to destroy it anyway.

syntax: destroy <class name>

Turn off class scheduling for the system. Note that the kernel will terminate the class scheduler daemon.

syntax: disable

Turn on class scheduling for the system. A daemon will be started that periodically examines class CPU usage and adjusts access of a class to the CPU depending on its percentage.

syntax: enable

Return to the command shell. If any permanent changes were made to the database, You will be asked to save or discard them. (Same as 'quit').

syntax: exit

On-line help. If a subcommand is specified, detailed information pertaining to that subcommand is displayed. Otherwise, a list of all subcommands and their arguments is displayed.

syntax: help [<subcommand>]

Return to the command shell. If any permanent changes were made to the database, You will be asked to save or discard them. (Same as 'exit').

syntax: quit

Change the name of an existing class.

syntax: rename <old name> <new name>

Write permanent database changes to the disk and continue.

syntax: save

List the configured classes, the CPU percentage allocated to each class, and members assigned to it. If no class name is specified, all classes will be shown.

syntax: show [<class name>]

List the current CPU utilization of a class. If no class name is specified, all classes will be shown.

syntax: stats [<class name>]

 

FILES

/etc/class.

 

RELATED INFORMATION

runclass(1), class_scheduling(4). delim off delim off


 

Index

NAME
SYNOPSIS
DESCRIPTION
FILES
RELATED INFORMATION

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Time: 02:40:29 GMT, October 02, 2010