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SYSTEM STARTUP

AND SHUTDOWN

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Introduction

This topic discusses how the systemenvironment should be managed.

It will explain the boot options suchas normal boot, maintenance boot,management services anddiagnostics.

And also it tells about startupprocess and shutdown process.

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Objectives

Describe the system startup process

Describe how to shutdown theprocess

Describe the contents of the/etc/inittab file

Manage the system environment

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Alog command

Description

The alog command reads standardinput, writes to standard output, and

copies the output into a fixed-size file. This works with log files that are

specified on the command line or with logsthat are defined in the alog configurationdatabase.

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Flags

-C

Changes the attributes for a specifiedLogType. Use the -C flag with the -f, -s,

and -w flags to change the File, Size, andVerbosity attributes for the specifiedLogType. The -t LogType flag is required.

-o

Lists the contents of LogFile. Writes thecontents of LogFile to standard output insequential order.

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-L

Lists the log types currentlydefined in the alog configurationdatabase.

-vWrites the current value of the

Verbosity attribute for LogType thatis defined in the alog configurationdatabase to standard output.

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Example

To list the contents of /tmp/sample.loglog file as,

alog -f /tmp/sample.log o

To record the current date and time in

a log file named sample. log,date | alog -f /tmp/sample.log

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Specified log Type

To display the current attributes of aspecified log type,

alog -L [ -t LogType ]

Example:

To change the name of the log file for thelog type sample to /var/sample.log in the

alog configuration database,alog -C -t sample -f /var/sample.log

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SYSTEM RESOURCE CONTROLLER

The system resource controller(SRC) provides a set of commands tomake it easier for the administrator

to control subsystems.Subsystem- A subsystem is a

program or set of related programsis designed to perform a function.This can be further divided intoSubservers.

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Subservers- subservers are similarto daemons.

Group- SRC was designed tominimize the need for userintervention since it provides controlof individual subsystem or group of

subsystems.Some subsystem have subservers.

For example the tcp/ip group

contains a subsystem, inetd, thatcontains several subservers forexample ftp and telnet.

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System Resource Controller Syntax

List SRC status1.The lssrc command is used to

show the status of SRC.

2. In following example we arechecking the status of spooler groupusing g.

# lssrc g spooler

3.To list the all processesa flag

is used.

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Start a subsystem

1.Startsrc command is usedto start the subsystems or groups.

2.In following example we arestarting the lpd subsystem.

# startsrc s lpd

3.-s and g options are usedto control the subsystems orsubsystem groups respectively.

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Stop a subsystem

1.Stopsrc is used to stop the

subsystems or groups.

2.lpd subsystem will be stoppedby following command.

# stopsrcs lpd

Kill command

Which processes are notcontrolled by SRC those can be stopped bykill command.

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Refresh a subsystem

1.Refresh command forcesthe subsystem to reread any of isconfiguration files.

2.Here we are refreshing thelpd daemon.

# refresh s lpd

3.lpd

The daemon thatcontrols the print server.

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System Shutdown

Gracefully stops all activity on thesystem and advises all log on users.

Warns users of a impendingshutdown.

The SMIT shutdown fastpath or theshutdown command is used to shutthe system down cleanly.

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Flags

-F Does the fast shutdown. -h Halts the operating system

completely.

-I Specifies interactive mode.

-k Avoids shutting down thesystem.

-m Brings the system down to

maintenance(singleuser)mode. -t Restarts the system on the date

specified by mmddHHMM.

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-r Restarts the system after being

shutdown with reboot command.

Example:

To shutdown the system tosingle user mode.

#cd /

#shutdown -m