Unit 9: Basic Linux Administration

Objectives
9: Administer and maintain a Linux system.
9.1: Create users and groups by using the CLI and GUI tools.
9.2: Back up a Linux system by using the tar utility.
9.3: Maintain effective logs by using the log rotate utility.

Readings
A Practical Guide to Fedora and Red Hat Enterprise Linux
Chapter 11, pp. 407-425 * Chapter 16

In-Class Assessment * Week 9 Quiz:

Homework
The following homework is designed to cover the course objectives for this unit.

Assignment 9.1:
Complete the following exercise in your textbook: * Chapter 16: Question 1-5 on page 643

Submit your written answer to your instructor at the start of Unit 10.

Labs
Instructor Notes: Assign students the following lab which can be printed from Appendix D.
Lab 9.1: Using tar to Back Up Files
What is the purpose?
This lab exercise lets you perform basic file backup on your Linux system.

What are the steps?
Task 1: Backing up with tar
Procedure
1. Open a terminal window as a regular user. 2. Create a directory named backup in your home directory. 3. Copy some files from your home directory into your new directory. 4. Create a backup of your new directory by using tar and compress the file with bzip2. Make sure that the backup file is not placed in the directory you are backing up. You will need to: a. Create permission. b. Choose verbose mode option. c. Choose the bzip2 file format. d. Specify the path for the file to be backed up. e. Set permissions. f. Set file flags for tar. Make sure you put a “.tar.bz2” extension on the tar file.

Task 2: Restoring from a tar backup
Procedure
1. Delete the backup directory with rm -rf backup. Be careful with this command. The –r tells rm to delete recursively, or to “drill down” through directories, deleting all the way down. The -f tells rm to force the job, or to do it without asking you first. It can be used to delete any directory and all subdirectories, including the root directory, if you have access. Do not use this command without making sure you want to use it. 2. Use tar and the backup file you created in Step 4 to restore the file. You will be extracting instead of creating the file this time, but all the other flags to tar will be the same. 3. Show your completed lab to your instructor.

Did it work?
Were you able to create the tar file?
Was the directory restored with all files and permissions?
Was it restored in the proper location?

Instructor Notes: Assign students the following lab which can be printed from Appendix D.
Lab 9.2: Creating Users and Groups
What is the purpose?
This lab introduces you to user management on Fedora and other Linux systems. What are the steps?
Task 1: Creating a user and a group using the GUI
Procedure
1. Run Users and Groups on the Administration tab on the System menu. 2. Provide the root password. 3. Click Add User and create a new user named Test Dummy with the account name tdummy and the password d8m4~1e. Note that you can also create a different home directory for the user and change the shell that the user can use. The user can also change shells by using the chsh command. 4. Click Add Group and create a new group called webdev. You will use this group next week. 5. Click the Groups tab to see the new group you created. 6. Double-click the group to edit it. When the Group Properties window opens, click the Group Users tab. 7. Scroll down and select the tdummy check box to add the account to the group. Add your account to the group. 8. Close User Manager when you are finished. Task 2: Creating a user and a group using the CLI
Procedure
1. Open a terminal window and become root.
Use the useradd command to create a new user with the account name lrat and the full name Lab Rat.
Use usermod to add the new account to the webdev group. Make sure that you pass the append group option with the usermod command to append the group. Otherwise, the account will be removed from all groups except webdev.
Using the tail command, take a look at /etc/passwd and /etc/group to confirm the creation of the new account and its addition to the webdev group.
Use tail to view /etc/shadow. In the password column in the file, you can see an encrypted password for tdummy but not for lrat. You should see two exclamation marks for the password for lrat. 6. Use the passwd command to set password as the password for lrat.
Check /etc/shadow again, and you should see an encrypted password for lrat. Show your completed lab to your instructor.

Did it work?
Were the accounts displayed in /etc/passwd and /etc/shadow?
Did you have passwords in /etc/shadow for both accounts?
Were both accounts added to the webdev group in /etc/group?
When you log off, do you see the new accounts listed on the login screen?

Instructor Notes: Assign students the following lab which can be printed from Appendix D.
Lab 9.3: Administering Logs
What is the purpose?
In this lab exercise, you will rotate log files with logrotate.

What are the steps?
Task 1: Using logrotate
Procedure
1. Open /etc/logrotate.conf with vim. 2. Set the rotation to occur daily. 3. Keep seven weeks’ worth of backlogs. 4. Tell logrotate to compress the backlogs. 5. Save the file and quit vim. 6. To force a rotation, run logrotate manually by typing: logrotate -f /etc/logrotate.conf 7. Show your completed lab to your instructor.

Did it work?
Obtain a listing from /var/log. Can you see compressed log files?
Are seven copies of logs maintained?

Summary and Reminders
Summary
In this unit, students were introduced to several basic aspects of Linux system administration. Managing software on a Linux system, backing up data, creating users and groups, and managing log files are all basic skills that students will need as they administer Linux servers.

Reminders
Remind students their homework assignment is due at the beginning of Unit 10.
In Lab 10.2, students will create a Web page to see Apache error-handling. Prepare an .html template and graphic for them to use in that lab.

(End of Unit 9)