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Index for Section 8 |
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Alphabetical listing for C |
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class_admin(8)
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:
1. 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.
2. 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.
3. 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 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 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 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 %>
configure Set up the basic class scheduling parameters. You will be
prompted for each parameter.
syntax: configure
delete 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 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>
disable Turn off class scheduling for the system. Note that the kernel
will terminate the class scheduler daemon.
syntax: disable
enable 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
exit 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
help 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>]
quit 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
rename Change the name of an existing class.
syntax: rename <old name> <new name>
save Write permanent database changes to the disk and continue.
syntax: save
show 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>]
stats 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).