Test 2 Study Set

The ______ daemon is the first process started on the system by the Linux kernel. It is responsible for loading all of the other daemons on the system required to bring the system to a usable state in which users can log in and interact with services.

init (Initialize)

Because the init daemon is responsible for starting and stopping daemons, and, hence changing runlevels, runlevels are often called ______.

initstates

The ___ filesystem is the CD-ROM filesystem which is a filesystem that originated from the International Standards Organization recommendation 9660 and is used to access data stored on CDs and DVDs.

iso9660

The ______ command lists all background processes running in the current shell.

jobs

When there are multiple background processes executing in the shell, the ______ command indicates the most recent background processes with a + symbol and the second most recent background processes with a - symbol. Commands operate on the most recent process, by default.

jobs

A ____ is an automated installation script that specifies the normal OS installation choices. It contains sections on system configuration, disk partitioning and package selection.

kickstart

A ______ command is the most common command used to terminate a process. It sends a kill signal to the process.

kill

The ______ command kills all instances of a process by the command name. It uses the process name instead of its PID. This is convenient for killing multiple processes with the same name.

killall

When an ext3 filesystem is created on a disk device, one directory called _____ is created by default.

lost+found

This command lists the files classified by file type in the /proc directory. The subdirectories that start with a number are used to display process information. Other directories can contain kernel parameters.

ls -F /proc

A ______ is a string of commands connected by the "|" metacharacters. The shell then sends the stdout on the left to the stdin on the right.

pipe

A ______ is a program that is running in memory and on the CPU.

process

Every process has a unique ______ that allows the kernel to identify it uniquely.

process ID (PID)

The ______ indicates what the process is currently doing. Most processes are either sleeping (S) or running (R).

process state

Without arguments, the ______ command simply displays a list of processes that are running in the current shell. It includes the PID, terminal, CPU time and the command that started the process.

ps

To create a PV partition, use the ____ command.

pvcreate

The _____ command is used to display detailed information about each PV.

pvdisplay

The ______ command takes user input from stdin and places it in a variable specified by an argument to the command.

read

Fault-tolerant configurations are typically implemented by a _____ . They can be used to speed up access to hard disks. It combines several hard disks' storage space. There are seven configurations.

redundant array of inexpensive disks (RAID)

The ______ command will alter the NI of a process after it is running.

renice

A ______ is a faulty process that consumes an excessive amount of system resources.

rogue process

The ______ command displays the current runlevel of the system and the previous runlevel.

runlevel

The ______ filter command searches for a certain string of text and replaces that text string with another text string.

sed

The ______ command can be used to list all environment variables in the BASH shell including user-defined variables.

set

The ______ command lists the environment variables and their current values.

set

A ______ is a text file containing a list of commands or constructs for the shell to execute. It may contain any command that can be entered on the command line.

shell script

A ______ is a shell created by current shell.

subshell

A _____ a power flaw, is a momentary increase in voltage. A surge protector is useful for minimizing its effects.

surge (surge protector)

A ______ command is a filter command that takes information from Standard Input and sends that information to a file, as well as to Standard Output.

tee

The ______ command can be used to change the PRI or to kill processes. The user can stop rogue processes immediately after they are identified since they appear at the top of this list for this command.

top

The ______ command displays an interactive screen listing processes organized by processor time. Processes that use the most processor time are listed at the top of the screen.

top

The ______ utility can also be used to change the NI value of running processes. The root user needs to press the r key, the PID & the nice value when prompted.

top

The ______ command can be used to replace characters in a file sent via Standard Input.

tr

The ____ filesystem is the Universal Disk filesystem which is a filesystem used by software programs that write to a CD-R, CD-RW or DVD writable disks & RW.

udf

The _____ command is used to unmount devices from mount point directories.

umount

The ____ command is used to create a VG that uses the space in PVs. The arguments are name of the VG and PVs to be used.

vgcreate

The ____ command is used to display detailed information about each VG.

vgdisplay

The _____ command is used to add a new PV to an existing VG.

vgextend

A ______ is a program that replicates itself so as to infect other computers.

virus

A ____ is a partition with its own filesystem.

volume

______ processes are processes that the BASH shell does not wait for termination. It uses the & metacharacter as part of the command and the user receives the BASH shell prompt immediately.

Background

A ____ contains one or more PVs. It represents the pool of hard disk storage space that is available to the LVM for creating logical volumes. Additional PVs can easily be added to a VG after creation.

volume group (VS)

When a process finished executing, the parent process must check to see if it executed correctly and then release the child process's PID so it can be used again. While a process is waiting for its parent process to release the PID, the process is said to be in a ______ state, because it has finished but retains a PID.

zombie

The command on the right of the ______ construct is executed only if the command on the left of the construct did not complete successfully.

||

State some of the common BASH shell environment files and the order in which they are executed.

~/.bashrc /etc/profile ~/.bash_profile ~/.bash_login ~/.profile

______ is an act of creating a new BASH shell and it is carried out with the fork function in the BASH shell. This new subshell then executes the binary program or shell script using its exec function. The original BASH shell waits for the subshell to complete. The subshell kills itself when it is done and then control returns to the original BASH shell.

Forking

____ are the limits on the number of files or total disk storage space on a hard disk drive that are available to the user. It will restrict the number of files/directories or total disk space usage for each user. It can be applied to both users and groups of users.

Hard disk quotas

____ are rigid quotas and prevent the user from exceeding these hard disk limits.

Hard limits

_____ are unused partitions on hard disks that the LVM can use to store information.

Physical volumes (PV's)

______ is the priority used by the kernel for the process. It is measured between 0 (high priority) and 127 (low priority).

Process priority (PRI)

____ requires two identical hard disks. In this RAID configuration, the same data is written to two separate hard disks at the same time. This results in two hard drives with identical information. It is fault tolerant.

Raid level 1 (also called disk mirroring)

T/F. Some commands on the Linux system only accept files when they are passed by the shell through Standard Input. Therefore to redirect stdin of a file, the user must use the "<" shell metacharacter.

T

T/F. The BASH shell clears the contents of the goodoutput file if it exists and creates the file if it does not exist.

T

T/F. The BASH shell is responsible for providing a user interface and interpreting commands entered on the command line. In addition, the BASH shell can manipulate command input and output, provided the user specifies certain shell metacharacters on the command line alongside the command.

T

T/F. The Bash shell clears a file that already exists before performing the redirection.

T

T/F. The LVM has error correction abilities that minimize the chance that data will be corrupted or lost.

T

T/F. The backup rotation scheme specifies when and how often backups will occur.

T

T/F. The case construct must end with esac ("case" backwards).

T

T/F. The device driver for the first USB drive is stored in the /dev/bus/usb directory.

T

T/F. The device driver for the mouse is stored in the /dev/input directory.

T

T/F. The df commands only views mounted filesystems.

T

T/F. The if construct controls the flow of the program based on true/false decisions.

T

T/F. To prevent the file from being cleared by the BASH shell and append output to the existing output, you can specify two ">" metacharacters alongside the file descriptor. The following is an example:date >>dateoutput

T

T/F. To see a list of devices that are currently used on the system and the major numbers, use the cat /proc/devices command.

T

T/F. To verify hardware settings, examine the contents of the /proc directory.

T

T/F. Vmlinuz-<kernel version> is the Linux kernel file.

T

T/F. When exiting the BASH shell, all variables stored in memory are destroyed along with the shell itself.

T

T/F. mtab= mount table

T

______ can be used to run multiple OSs at the same time.

Virtualization software

A ______ modifies the "look and feel" of X Windows.

Windows Manager

______ are technically not viruses, but rather programs that run independently and travel between computers across networks. They can carry and hide viruses. They eat up bandwidth.

Worms

______ is a core component of the Linux GUI. It provides the ability to draw graphical images in windows that are displayed on the terminal screen.

X Windows

______ performs most of the graphical functions in a GUI.

X Windows

The programs that tell X Windows how to draw the graphics and display the results are known as ______.

X clients

______ draws the graphics requested by the X client.

X server

The ______ daemon is a system daemon that executes tasks once at a future time.

at

The ______ command is used to view the contents of the shell environment at the time the at job was scheduled.

at -c

The ______ command is used to delete a scheduled job.

at -d

The ______ command is used to run scheduled jobs from a shell script.

at -f

The _____ command is used to view a list of scheduled jobs.

at -l

The ______ filter command searches for patterns of text and perform some action on the text found. This command treats each line of text as a record in a database and each word in a line as a database field.

awk

System maintenance, backups, and CPU-intensive tasks are often scheduled during non-business hours and are often scheduled by the ______ daemon.

cron

The ______ daemon is a system daemon that executes tasks repetitively in the future.

cron

A ______ is a system process that performs useful tasks, e.g., printing, scheduling and OS maintenance.

daemon

A ______ is a system process that is not associated with a terminal.

daemon process

After the Linux kernel is loaded into memory, the boot loader is no longer active. The Linux kernel continues to initialize the system by loading ______ into memory.

daemons

The ____ command monitors the free space used by mounted filesystems. This command with the -h option is more user friendly or at least humanly-readable.

df (disk free space)

A ______ backup occurs when only data that have changed since the last full backup are copied to a storage medium.

differential

The PRI is ______ related to the amount of time slices a process has on the CPU.

directly

The ____ command views the size of a directory and contents in Kilobytes

du (directory usage)

The ____ command views the total number of inodes and free inodes for an ext2, ext3 or ext4 filesystem. The -h option should be used.

dumpe2fs

The ______ command views the contents of a specified variable and uses the prefix $ shell metacharacter.

echo

The ______ command lists all exported environment and user-defined variables in the shell.

env

The ______ store variables and values and are executed each time the BASH shell is started to ensure variables are always accessible. The user can put the values in a file to ensure that variables are accessible to a shell at all times.

environment files

The _____ file is used to mount devices at boot time and it is also consulted when users do not specify enough arguments with the mount command.

etc/fstab (filesystem table)

The ______ command is used to export user-defined variables to the subshells and it ensures that the programs started by the current shell have access to these variables.

export

The ___ filesystem is the second extended filesystem which is the traditional filesystem used in Linux. It supports access control lists (individual user permissions).

ext2

The ____ filesystem is the third extended filesystem which is a variation on ext2 that allows for journaling and thus, has a faster startup and recovery time.

ext3

The ___ filesystem is the fourth extended filesystem which is a variation on ext3 that has larger filesystem support and speed enhancements.

ext4

The ____ command creates partitions after installation. The user needs to specify the hard disk partition as an argument.

fdisk

Filesystems themselves can accumulate errors over time and these errors are often referred to as ____ and are common on most filesystems.

filesystem corruption

After a background process has been started, the ______ command moves this background process to the foreground.

foreground (fg)

The _____ command checks a filesystem for errors.

fsck (filesystem check)

A ______ backup occurs when all data on all of the servers are copied to a storage medium.

full

A ______ is the first line in a shell script and it specifies the pathname to the shell that interprets the contents of the shell script.

hashpling

The following is the format for the if construct.

if this is true then do these commands elif this is true then do these commands else do these commands fi

A negative nice value ______ the likelihood that the process will receive more time slices, whereas a positive nice value does the opposite.

increases

A(n) ______ backup occurs when only data that have changed since the last backup of any type are copied to a storage medium.

incremental

Although the system administrator cannot change the PRI value directly, the nice (NI) value can be set to ______ affect the priority of a process.

indirectly

Recall that after a boot loader loads the Linux OS kernel into memory, the kernel resumes control and executes the first daemon process called the ______ daemon on the system.

init

The ______ command changes the OS runlevel.

init

The first process started by the Linux kernel is the ______ daemon, which has a PID of 1 and a PPID of 0 referring to the kernel itself.

init

The command on the right of the ______ construct is executed only if the command on the left of the construct completes successfully.

&&

The ____ directory grows in size continuously as it stores log files. Old log files should be removed periodically to leave room for new ones.

/var

To view system processes that started successfully and unsuccessfully during boot time, view the contents of the ____.

/var/log/messages log file

The at daemon uses the current shell's environment when executing scheduled commands. The shell environment and scheduled commands are stored in the ______ directory.

/var/spool/at

By default, a process starts with a NI value of ______.

0

There are six fields in the etc/fstab file. State these fields.

<device to mount> <mount point> <type> <mount options> <dump#> and <fsck#>

T/F. Proc is where the hardware stuff is.

T

T/F. RAID can be hardware-based, software-based or firmware-based.

T

T/F. RAID level 0 configurations are not fault-tolerant.

T

T/F. Redirection only occurs from a command to a file and vice versa.

T

The ______ directory is the directory that contains the Linux kernel.

/boot

The __ directory contains a device file for each device on your computer.

/dev

The ______ is a file listing all of the users that are able to use the at command.

/etc/at.allow

The ______ is a file listing all of the users that are not able to use the at command.

/etc/at.deny

The ______ file is consulted to start or stop daemons and thus to change runlevels.

/etc/inittab

The ______ file is the configuration file for the init daemon. It uses its configuration file to determine the number of daemons that need to be loaded on the system to provide system services and ultimately allow users to log in and use the system. Furthermore, it is also responsible for unloading daemons that are loaded in memory when the system is halted or rebooted.

/etc/inittab

The ______ file is always executed immediately after login for all users on the system and sets most environment variables, such as HOME and PATH.

/etc/profile

Quotas are typically enabled at boot time if there are entries in ____ file.

/ets/fstab

The ____ directory contains most utilities and installed programs on a Linux system and should have enough room for future software installations.

/usr

A _____ a power flaw, is a complete power loss. A generator is useful for minimizing its effects.

Blackout (generator)

A ______, a power flaw, is a momentary decrease in voltage. A power conditioner is useful for minimizing its effects.

Brownout or sag (power conditioner)

______ are unwanted programs transmitted to a computer without the user's knowledge. It designed to damage data and software (does not physically damage the PC hardware).

Computer infestations

______ has parts of several physical disks linked together in an array. Data and parity information are written to all disks in this array. If one disk fails, the data may be reconstructed from the parity information written on the other hard drives. It uses space efficiently.

Disk Striping with Parity (RAID 5)

______ requires two disks, configured to work in tandem. One disk is an exact copy of the other disk. If one disk fails, then the data remains accessible. It is simple to set up and makes recovery from disk failures easy. It requires twice as much disk space.

Disk mirroring (Raid 1)

____ is another type of RAID level 0 that is used to write a portion of an individual file to each of multiple hard drives. Each hard disk stores a section of the file. While it is not fault-tolerant, it decreases the read/write time of the data written to the hard drives.

Disk striping

______ are an arrangement of physical or logical disks such that, if one disk fails, the data remains accessible without requiring restoration from backups. It is based on standard terminology for RAID (Redundant Arrays of Inexpensive Disks).

Fault-tolerant systems

______ processes are processes that the BASH shell must wait for termination.

Foreground

______ a power flaw, is a fluctuation in voltage levels caused by other devices on the network. A line or power conditioner is useful for minimizing its effects.

Line noise (line or power conidtioner)

_____ is used to create volumes. These volumes can contain filesystems and can be mounted to directories. They are more flexible than standard partitions because they allow use of free space across multiple hard disks. They have error correction abilities.

Logical Volume Manager (LVM)

____ are the usable volumes that are created by the LVM from the available storage space within a VG. LVs contain a filesystem and are mounted to a directory in the Linux filesystem hierarchy. In addition, LVs can be resized easily by the LVM to use more or less storage space.

Logical volumes (LV's)

______ execute commands repetitively. They alter the flow of a program based on the results of a particular statement. They repeat parts of the program until it reaches the desired result. They can be used to process a list of objects, such as files, directories, users, printers and so on. The for construct is an example.

Loop constructs

A __ is a directory to which a device is attached.

Mount point

____ a drive refers to the process of making a device accessible to users via the logical directory tree.

Mounting

____ is the most common RAID configuration. It requires a minimum of three hard disks for implementation. The parity information is not written to one drive as in other RAID levels. It writes portions of the information to different hard drives and maintains the parity information. It is fault tolerant.

Raid level 5 (also called disk striping with parity)

The only kill signal that cannot be trapped by any process is the ______.

SIGKILL (9)

______ is a technique that links multiple servers together to act as a single server.

Server clustering

______ is a fault tolerance technique in which one server duplicates the transactions and data storage of another server.

Server mirroring

____ allow the user to extend the hard disk quota limits for a certain period of time (usually seven days by default).

Soft limits

____ is one type of RAID level 0 in which two hard drives are seen as one single volume by the system. It is useful when a large amount of space is needed in a single volume without fault-tolerance.

Spanning

______ is software used to collect and relay information about a user or the web sites a user visits to advertisers.

Spyware

_____ is a file descriptor that refers to any error messages generated by the command.

Standard Error ( stderr)

____ is a file descriptor that refers to the information processed by the command during execution, and is often takes the form of user input typed on the keyboard.

Standard input (stdin)

____ is a file descriptor that refers to the normal output of a command.

Standard output (stdout)

T/F. A BASH shell has several variables in memory at any one time.

T

T/F. A filesystem with several small files might use up all of the inodes in the inode table and prevent new files from being created on the filesystem.

T

T/F. After /etc/profile finishes executing, the home directory of the user is searched for the hidden environment files .bash_profile, .bash_login and .profile.

T

T/F. After a flash drive has been formatted with a filesystem, it must be mounted on the directory tree before it can be used.

T

T/F. After rebooting the computer, the partition must be formatted, then mounted and unmounted.

T

T/F. Any existing directory can be a mount point. The existing files are just covered up in the directory.

T

T/F. CDs typically use the iso9660 filesystem type and are not writable. They should be mounted with the -r (read-only) option.

T

T/F. CDs/DVDs cannot be ejected until properly unmounted because the drive is locked.

T

T/F. Don't run any program that you cannot verify its origin.

T

T/F. Each partition in a Linux system can have its own unique filesystem.

T

T/F. Files that cannot be repaired are placed in the lost+found directory and the file is renamed as its inode number. These files in the lost+found directory are usually deleted.

T

T/F. If a device file is corrupted, it will be listed as a regular file.

T

T/F. It is good form to always reboot your machine after running fdisk to ensure proper reloading of the partition table into memory.

T

T/F. Kickstart files are text files and can be edited with a text editor.

T

T/F. Most removable storage devices emulate the SCSI protocol in the firmware of the device itself. Therefore, USB devices can usually be configured as SATA or SCSI hard drives, i.e., /dev/sda, /dev/sdb, /dev/sdc & /dev/sdd.

T

T/F. Normally, only one operating system can be active at any one time.

T

A ______ disguises itself as something useful but actually harms your system. It is technically not a virus since it does not replicate itself.

Trojan horse

A foreground process can be paused with Ctrl+z combination and sent to the background with the ______ command.

background (bg)

The ______ is a program used to load an operating system.

boot loader

The primary function of a ______ during the boot process is to load the Linux kernel into memory.

boot loader

The ______ construct compares a value of a variable with several different patterns of text or numbers.

case

Each process can start an unlimited number of other processes. These new processes are called ______.

child processes

To view the information that Linux has detected regarding the CPU in the computer, simply view the contents of the____ in the /proc directory.

cpuinfo file

The _____ command is used to display information about each LV.

lv display

The ____ command is used to create LVs from available space in a VG.

lvcreate

The ____ command is used to increase the size of an LV, e.g., to use space extended onto an existing VG.

lvextend

To verify that Linux has detected the correct amount of RAM in the system after installation, simply view the contents of the ____ in the /proc directory.

meminfo file

The ____ command with the -t option allows the system administrator to specify the filesystem type.

mkfs

The _____ command is used to format a disk device with a filesystem.

mkfs (make filesystem)

The ___ command can be used to re-create a corrupted device file or recreate a deleted file. The command must have the file type, the major and minor numbers.

mknod

The ___ command is used to mount devices to mount point directories.

mount

The ______ command with no options or arguments displays a list of currently mounted filesystems in the /etc/mtab file.

mount

The ______ command changes a process's priority as it starts.

nice

The ______ can be used to affect the process priority indirectly. It is measured between - 20 (a greater chance of a high priority) and 19 (a greater chance of a lower priority).

nice value (NI)

Each process must be started by an existing process. This existing process is called a ______.

parent process

As a result, each process has a ______ which identifies the process that started it.

parent process ID (PPID)

A ____ is a physical division of a hard drive.

partition