378 Chapter 11 Study Guide

Answers to Chapter Questions

Chapter Pre-test

1.The tar command, which stands for tape archive, archives several files into one single file for easier storage on disk or tape.

2.Runlevel 0 indicates a halted system that is shutdown.

3.If you don’t shut down your Linux system properly with the shutdown or init commands, you risk causing damage to your hard drive data because the file systems aren’t properly unmounted before shutdown.

4.The process that runs the print spooler is lpd.

5.Startup scripts are located in /etc/rc.d or /etc/init.d.

6.“S” stands for a start script, which will start a process, and “K” stands for kill script, which will kill a process.

7.To enter command mode in the vi editor, hit Escape.

8.The Graphical User Interface (GUI) will run in runlevel 5.

9.To print from the command line, use the lpr command.

10.With the tar command, use tar -xvf [filename].

Assessment Questions

1.C. In the /etc/inittab file, the default runlevel is probably set to 0, which tells it to shutdown right after the system has started. For review, see the “Linux Runlevels” section.

2.B. The correct command is shutdown -h 100 to perform this action. For review, see the “Shutting down Linux” section.

3.A. This script is a startup script for the system’s networking processes. For review, see the “Startup scripts” section.

4.D. Runlevel 5 is used to boot up a full multiuser system and to automatically start X-windows. For review, see the “Linux Runlevels” section.

5.B. The Line Printing Daemon (lpd) controls the print spooling process, and is started automatically at boot time. For review, see the “Printing management” section.

6.C. The correct location is the /etc/inittab file. For review, see the “Linux Runlevels” section.

7.A. The correct command is :wq used in command mode. For review, see the “Using the vi Editor” section.

8.D. The tar command doesn’t compress data. To compress data, use the gzip or compress command. For review, see the “Using the tar command” section.

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9.B. The halt command will shut down a Linux system without rebooting. For review, see the “Shutting down Linux” section.

10.A. init 1 will bring the system to single-user mode. For review, see the “Linux Runlevels” section.

11.C. The correct command to check the printer queue status is lpq. For review, see the “Printing management” section.

12.B. The reload command will tell the system to stop the service, reload the configuration file, and restart the service. For review, see the “Managing Linux Services” section.

13.A. The file that contains specific printer configuration information is /etc/printcap. For review, see the “Printing management” section.

14.D. The command to reboot a Linux system is reboot. For review, see the “Shutting down Linux” section.

15.D. To insert text in the vi editor, you must be in insert mode. For review, see the “Using the vi Editor” section.

16.C. Because the service is currently not running, use the start command. For review, see the “Managing Linux Services” section.

17.A. To extract files from an archive, use the -x argument in the tar command. For review, see the “Using the tar command” section.

18.A. init runlevel 6 is used to shut down and reboot the system. For review, see the “Linux Runlevels” section.

19.B. The correct location for the startup scripts for runlevel 5 is /etc/rc.d/rc5.d. For review, see the “Linux Runlevels” section.

20.D. The correct command to quit without saving in the vi editor is :q! in the command mode. For review, see the “Using the vi Editor” section.

Scenarios

1.Because the DNS process (named) is already running, it may be in a locked state. Use the following commands to change into the startup script directory for the process, and then restart the service.

cd /etc/rc.d/init.d

./named restart

If you encounter no other problems, such as with the configuration file, the service should recover.

2.To change the default runlevel, edit the configuration file for init, which is /etc/inittab.

Use the vi editor to edit the file using the following command: vi /etc/inittab

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Use the cursor keys to jump down to the line that reads:

id:5:initdefault:

Position the cursor over the number 5, and hit the x key to delete the character. Press the letter i to enter insert mode, and type the number 3.

The new entry should look like the following:

id:3:initdefault:

Now enter command mode by pressing Escape, and then use the following command to save the file:

:wq

Now reboot the system, and it should boot up into runlevel 3, without the X windows.

384 Part V Maintaining the Linux System

CHAPTER PRE-TEST

1.What is the function of cron?

2.What kind of file has a tar.gz extension?

3.What kinds of information can the ifconfig command show you?

4.After creating a partition, what command do you use to make a file system?

5.Why should core dumps be analyzed?

6.What is the purpose of a program patch?

7.How does the at function differ from cron?

8.How can the fsck command help fix disk errors?

9.What is the best time to perform system updates and upgrades?

10.What is the purpose of the fdisk command?

Answers to these questions can be found at the end of the chapter.