Self Test

The following questions will help you measure your understanding of the material presented in this chapter. As no multiple choice questions appear on the Red Hat exams, no multiple choice questions appear in this book. These questions exclusively test your understanding of the chapter. It is okay if you have another way of performing a task. Getting results, not memorizing trivia, is what counts on the Red Hat exams. There may be more than one answer to many of these questions

The Basics of the Kernel

1.	You are troubleshooting someone else's computer and are not sure what network card is inside it. You have checked the output from the dmesg command, but no network cards are listed, and even though you have a bunch of compiled network modules, none are currently loaded. What command might load the unknown network device? __________________________________________________________________
2.	What directory includes dynamic kernel configuration settings? __________________________________________________________________

Answers

1.	Any of these commands might load the unknown network device: modprobe -lt net, modprobe, and modprobe eth0.
2.	The directory that includes dynamic kernel configuration settings is /proc.

New Kernels, the Easy Way

3.	When you install a newer kernel from a Red Hat RPM, what else do you need to do before rebooting? __________________________________________________________________
4.	What happens if you use the -U switch to install a later Red Hat kernel RPM? __________________________________________________________________

Answers

3.	When you install an updated kernel from a Red Hat RPM, you shouldn't have to do anything else. As configured, it should automatically create an initial RAM disk in the /boot directory and add an appropriate stanza to the GRUB configuration file, /boot/grub/grub.conf.
4.	If you use the rpm -U command, instead of rpm -i, you overwrite the currently active kernel. Since you're running from that kernel, you know that the active kernel works. If you overwrite it with a new kernel, and that new kernel doesn't work, you're out of luck.

Kernel Sources

5.	Your kernel is version 2.6.19, and your architecture is x86_64. When you install and build the source code package associated with the Red Hat kernel, you'll find it in what directory? __________________________________________________________________
6.	When you install the kernel source code, you'll find kernel-2.6.spec in the /usr/src/redhat/SPECS directory. What command would you run to unpack the source code? __________________________________________________________________

Answers

5.	If your kernel is some version 2.6.19, and your architecture is x86_64, the kernel source code when installed can be found in the /usr/src/redhat/BUILD/kernel-2.6.19/linux-2.6.19.x86_64 directory.
6.	When you install the kernel source code, with the kernel-2.6.spec in the /usr/src/redhat/SPECS directory, you can navigate to that directory and then unpack the code with the rpmbuild -bb kernel-2.6.spec command.

Recompiling a Kernel

7.	Once you've navigated to the directory with the kernel source code, name two commands that would open a menu that can help you configure a custom kernel. Assume all necessary dependencies are also installed. __________________________________________________________________ __________________________________________________________________
8.	You have just compiled and installed a custom kernel from kernel.org. What two other things do you need to do before you restart and boot from that kernel? __________________________________________________________________ __________________________________________________________________

Answers

7.	Once you've navigated to the directory with the kernel source code, there are not just two, but four commands available that open a menu that can help you configure a custom kernel: make config, make menuconfig, make xconfig, and make gconfig.
8.	You have just compiled and installed a custom kernel RPM. The two other things do you need to do before you restart and boot from that kernel is create an initial RAM disk with the mkinitrd command and create a new stanza in the GRUB configuration file, /boot/grub/grub.conf.

Advanced Partitioning: Software RAID

9.	In what file can you find the current software RAID configuration? __________________________________________________________________
10.	What command can help you build a new RAID array? Just list the basic command; assume that you'll go to the man page for more information. __________________________________________________________________

Answers

9.	You can find the current software RAID configuration in /proc/mdstat.
10.	The mdadm command can help you build a new RAID array.

Advanced Partitioning: Logical Volume Management

11.	Once you've created a new partition and set it to the Logical Volume Management filetype, what command adds it as a PV? __________________________________________________________________
12.	Once you've added more space to an LV, what command would expand the formatted filesystem to fill the new space? __________________________________________________________________

Answers

11.	Once you've created a new partition and set it to the Logical Volume Management filetype, the command that adds it as a PV is pvcreate. For example, if the new partition is /dev/hdb2, the command is pvcreate /dev/hdb2.
12.	Once you've added more space to an LV, the command that would expand the formatted filesystem to fill the new space is resize2fs.