Section 22.2. Boot, Initialization, Shutdown, and Runlevels (Topic 1.106)

22.2. Boot, Initialization, Shutdown, and Runlevels (Topic 1.106)

22.2.1. Review Questions

1. Name and briefly describe the two parts of LILO. Which part has a configuration file and what is that file called?

2. What are the ramifications relating to new hardware when running a monolithic kernel?

3. Which three runlevels are well-defined across Linux distributions, and what actions do they perform?

4. Describe a situation that would imply the need to switch to single-user mode.

5. How can you shut down and halt a Linux system immediately using shutdown?

22.2.2. Exercises

22.2.2.1. Exercise 1.106-1. Boot

1. Examine the contents of /etc/lilo.conf. How many kernel images or operating systems are configured for load by LILO? Explain the options you find in the file.

2. Install the boot loader by executing lilo. What happened?

3. Boot your system and manually specify the root filesystem using the root= keyword at the LILO prompt. What happens if you specify the wrong partition?

4. Use dmesg and less to examine boot-time messages. Compare what you find to the latest boot messages found in /var/log/messages.

5. Boot your system and use the single or 1 option to boot directly into single-user mode.

22.2.2.2. Exercise 1.106-2. Runlevels

1. After booting to single-user mode, switch to your normal runlevel using init n.

   1. Does the system come up as expected?

   2. Enter init 1 to go back to single-user mode. What daemons are still running?

2. Familiarize yourself with the contents of a few of the scripts in /etc/init.d (your system directories may vary).

3. Look in rc0.d through rc6.d for links to the scripts you examined. How are the scripts used? In which runlevels is the corresponding service active?

4. Shut down your system with init 0.

5. Shut down your system with shutdown -h now.