Determine and Configure Hardware Settings (2)

Question 1

Your system has SCSI disks. What device file represents the 2nd disk on the system’s third partition?

1. /dev/hda3
2. /dev/sda3
3. /dev/sr2
4. /dev/hdb3
5. /dev/sdb3
6. /dev/fd2

Answer 1

5. /dev/sdb3

SCSI devices are represented by /dev/sd* device files. The first disk would be listed as a, while the second disk is listed as b. Finally, the partition numbers start at 1 for the 1st partition, 2 for the second and so on. Therefore, the correct device file name for this disk is /dev/sdb3.

Question 2

Which of the following is true concerning Logical Volume Management (LVM)?

1. LVM uses logical volumes instead of directly using disk partitions.
2. LVM logical volumes are made up portions from a single designated volume group.
3. LVM volume groups are made up of one or more physical volumes.
4. LVM physical volumes are actually disk partitions that have been designated to be a physical volume.
5. Even if a partition is hasn’t been designated as a LVM physical volume, it can be in a LVM volume group.

Answer 2

1. LVM uses logical volumes instead of directly using disk partitions.
2. LVM logical volumes are made up portions from a single designated volume group.
3. LVM volume groups are made up of one or more physical volumes.
4. LVM physical volumes are actually disk partitions that have been designated to be a physical volume.

All of the statements are true, except, “Even if a partition is hasn’t been designated as a LVM physical volume, it can be in a LVM volume group.” A disk partition CANNOT participate in a volume group, if it is has not yet been designated as a LVM physical volume.

Question 3

Your system has two optical drives. What device file represents the 2nd optical drive?

1. /dev/hda2
2. /dev/sda2
3. /dev/sr1
4. /dev/hdb2
5. /dev/sdb2
6. /dev/fd1

Answer 3

3. /dev/sr1

Optical devices are represented by /dev/sr* device files. The first device would be listed as 0, while the second disk is listed as 1, and so on. Therefore, the correct device file name for the second optical device on this system is /dev/sr1.

Question 4

Which of the following files does the lsdev utility pull its information to display from?

1. /proc/dma
2. /proc/interrupts
3. /proc/filesystems
4. /proc/scsi
5. /proc/ioports
6. /proc/swaps

Answer 4

1. /proc/dma, 2. /proc/interrupts AND 5. /proc/ioports

The lsdev utility pulls its information to display from the /proc/dma, /proc/interrupts, and /proc/ioports files.

Question 5

Which of the following could be considered a kernel module?

1. device drivers
2. filesystem drivers
3. memory drivers
4. network drivers
5. system calls
6. executable loaders

Answer 5

1. device drivers
2. filesystem drivers
3. network drivers
4. system calls
5. executable loaders

Kernel modules include device drivers, filesystem drivers, network drivers, system calls, and executable loaders.

Question 6

Where are kernel module files stored in the Linux directory structure?

1. /dev/
2. /lib/modules
3. /dev/drivers
4. /proc/driver
5. /proc/module
6. /var/lib/modules

Answer 6

2. /lib/modules

Kernel module files are stored in the /lib/modules/ directory tree. There are specific to particular kernels, and typically stored in /lib/modules/*/kernel/drivers, where * is a wildcard for the Linux kernel version.

Question 7

Where are udev rules stored in the Linux directory structure?

1. /sys
2. /etc
3. /proc
4. /dev
5. /lib
6. /var/lib

Answer 7

2. /etc

The udev rules stored in the /etc directory, more specifically in the /etc/udev/rules.d/ directory.

Question 8

Name two essential commands to identify connected devices in a Linux system and what they do.

Answer 8

lspci will show all devices connected to the PCI bus.

lsusb will show connected USB devices.

Question 9

In order for a hardware device to be fully operational within a Linux system, what software component is required?

Answer 9

Hardware requires kernel modules and kernel drivers to be fully operational.

Question 10

What command, including arguments, would you execute to get kernel modules for a PCI device with address 00:14.0?

Answer 10

lspci -s 00:14.0 -k will display kernel drivers for the device and the kernel modules capable of handling it.

Question 11

What command, including arguments, show USB devices mappings as a hierarchical tree?

Answer 11

lsusb -t shows displays usb mappings as a tree.

Question 12

What Linux package provides tools to handle common tasks with Linux kernel modules.

Answer 12

The kmod package

Question 13

What information does the lsmod command provide?

Answer 13

The lsmod command lists all the loaded kernel modules, their size and which modules are using /dependent on the module.

Question 14

What command, including argument, can be used to remove a module from a running system?

Answer 14

modprobe -r <module> will remove a module.</module>

Question 15

If a kernel module is causing an issue, how can it be prevented from loading?

Answer 15

The module can be added to /etc/modprobe.d/blacklist.conf OR preferably a separate configuration file can be created, /etc/modprobe.d/<module_name>.conf.</module_name>

Question 16

What command displays information about Linux kernel modules?

Answer 16

modinfo displays information about kernel modules including author, description, license, parameters and filename.

Question 17

What is unique about the /proc and /sys filesystems with respect to traditional filesystems?

Answer 17

/proc and /sys are pseudo filesystems and exist RAM, not on disk partitions. They only exists while a system is running.

Question 18

Which Linux file stores detailed information about the CPU?

Answer 18

/pro/cpuinfo

Question 19

Which Linux file can identify which device is generating large numbers of interrupts?

Answer 19

/proc/interrupts

Question 20

Which Linux file stores currently registered Input/Output port regions in use?

Answer 20

/proc/ioports

Question 21

Which Linux file stores registered DMA (direct memory access) channels in use?

Answer 21

/proc/dma

Question 22

Which Linux subsystem is responsible for handling removable devices?

Answer 22

Removable devices, also known as hot-pluggable, are managed by udev.

Question 23

Which linux system directory is associated with mass storage devices?

Answer 23

/dev

Question 24

Suppose an operating system is unable to boot after adding a second SATA disk to the system.
Knowing that all parts are not defective, what could be the possible cause for this error?

Answer 24

The boot device order should be configured in the BIOS setup utility, otherwise the BIOS may
not able to run the bootloader.

Question 25

Suppose you want to make sure the external video card connected to the PCI bus of your newly
acquired desktop computer really is the one advertised by the manufacturer, but opening the
computer case will void the warranty. What command could be used to list the details of the
video card, as they were detected by the operating system?

Answer 25

lspci
lspci will list detailed information about all devices currently connected to the PCI
bus.

Question 26

The following line is part of the output generated by command lspci:

03:00.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS 2208 [Thunderbolt]
(rev 05)

What command should you execute to identify the kernel module in use for this specific
device?

Answer 26

lspci -s 03:00.0 -k
or
lspci -s 03:00.0 -v

Question 27

A system administrator wants to try different parameters for the bluetooth kernel module
without rebooting the system. However, any attempt to unload the module with

modprobe -r bluetooth

results in the following error:

modprobe: FATAL: Module bluetooth is in use.

What is the possible cause for this error?

Answer 27

The bluetooth module maybe in use by a running application.