Free Practice Questions for LPI 101-500 Exam

 The apt-get command upgrade will install the newest versions of all currently installed packages without removing any packages or installing new packages that are not already installed. It will only upgrade packages that can be upgraded without changing the dependencies1. The syntax is: apt-get upgrade. For example, apt-get upgrade nginx will update the nginx package to the latest version available in the repositories, if there is one2. The other options are not correct because:

auto-update is not a valid apt-get command.

dist-upgrade will also install new packages or remove existing packages if that is required to resolve a package conflict1. It is more aggressive than upgrade and may change the system in unexpected ways3.

install will install new packages or upgrade existing packages to the specified version1. It may also install or remove dependencies as needed4.

update will only resynchronize the package index files from the sources, but it will not install or upgrade any packages1. References:

apt-get(8) — apt — Debian buster — Debian Manpages

How to Update Nginx on Ubuntu 18.04 | Linuxize

What is “dist-upgrade” and why does it upgrade more than “upgrade”? - Ask Ubuntu

How to Install Specific Version of Package using apt-get - TecAdmin

 The function key that is used to start Safe Mode in Windows NT is none of the above, because Windows NT does not support Safe Mode. Safe Mode is a diagnostic mode of Windows that starts the system with minimal drivers and services, allowing the user to troubleshoot problems and restore the system to a normal state1. Safe Mode was introduced in Windows 95 and later versions, but not in Windows NT 4.0 and earlier2.

The other options are incorrect for the following reasons:

F10. This function key is used to access the Recovery Console in Windows XP, which is a command-line interface that allows the user to perform various administrative tasks, such as repairing the boot sector, restoring the registry, or copying files3. The Recovery Console is not the same as Safe Mode, and it is not available in Windows NT.

F8. This function key is used to access the Advanced Boot Options menu in Windows Vista and later versions, which allows the user to choose from various boot modes, including Safe Mode, Last Known Good Configuration, Debugging Mode, and others4. In Windows NT, pressing F8 during startup only displays a simple menu with three options: Normal, VGA mode, and Boot Logging5. None of these options are equivalent to Safe Mode.

F6. This function key is used to load additional drivers during the installation of Windows, such as SCSI or RAID drivers, from a floppy disk or a USB flash drive6. This function key has nothing to do with Safe Mode, and it is not relevant after the installation is completed.

 When removing a package on a system using dpkg package management, the --purge option ensures that configuration files are removed as well. The --purge option is equivalent to the --remove option followed by the --purge-config-files option, which removes any configuration files that are marked as obsolete. The --remove option only removes the package files, but leaves the configuration files intact. The --clean option removes any .deb files from the local cache, but does not affect the installed packages. The --delete option is not a valid option for dpkg. References:

1, 102.4 Lesson 1

3, 101-500 Exam - Free Questions and Answers - ITExams.com

man dpkg

 According to the FHS (Filesystem Hierarchy Standard), the /usr/share/doc directory is used to store documentation files for various packages installed on the system. The documentation files may include README files, manuals, license agreements, changelogs, etc. The /usr/share/doc directory is intended to be read-only and independent of the machine architecture. The other directories are not compliant with the FHS or do not exist by default. The /usr/share/documentation directory is not a standard directory and may not be recognized by some applications. The /usr/local/share/documentation directory is also not a standard directory and may conflict with the /usr/local/share/doc directory, which is used for documentation files for locally installed packages. The /var/share/doc directory does not exist by default and is not a valid subdirectory of /var, which is used for variable data files. The /etc/share/doc directory does not exist by default and is not a valid subdirectory of /etc, which is used for configuration files. References:

LPI 101-500 Exam Objectives, Topic 101.3, Weight 2

LPI Learning Materials, Chapter 1.3, Finding Linux Documentation

Web Search Results, 1

The correct permissions and ownership for the file /etc/passwd are:

B. -rw-r–r-- 1 root root 531 Jun 5 22:45 /etc/passwd

The /etc/passwd file is a plain text-based database that contains information for all user accounts on the system. It is owned by root and has 644 permissions. The file can only be modified by root or users with sudo privileges and readable by all system users. The permissions and ownership of the file are important for the security and functionality of the system. The permissions and ownership of the file can be viewed by using the ls -l command. For example:

ls -l /etc/passwd

The output of the command will show the following information:

-rw-r–r-- 1 root root 531 Jun 5 22:45 /etc/passwd

The first column shows the permissions of the file, which are composed of 10 characters. The first character indicates the file type, which is - for regular files. The next nine characters indicate the permissions for the user (owner), the group, and the others, respectively. Each set of three characters indicates the read ®, write (w), and execute (x) permissions. A dash (-) means no permission. In this case, the permissions are:

rw- for the user, which means the user can read and write the file, but not execute it.

r-- for the group, which means the group can only read the file, but not write or execute it.

r-- for the others, which means the others can only read the file, but not write or execute it.

The second and third columns show the owner and the group of the file, which are both root. The root user is the superuser or the administrator of the system, who has full access and control over the system. The root group is the primary group of the root user, which usually has no other members.

The fourth column shows the size of the file in bytes, which is 531 in this case. The fifth and sixth columns show the date and time of the last modification of the file, which are Jun 5 22:45 in this case. The last column shows the name of the file, which is /etc/passwd in this case.

The other options are not correct because:

A. -rw------- 1 root root 531 Jun 5 22:45 /etc/passwd: This option has the wrong permissions for the file. The permissions are 600, which means only the user (root) can read and write the file, and the group and the others have no permissions at all. This would prevent the system users from reading the file, which would cause problems for the login process and other utilities that rely on the file.

C. -rw-r–r-- 1 1 531 Jun 5 22:45 /etc/passwd: This option has the wrong owner and group for the file. The owner and group are both 1, which is the numeric ID of the user and group. However, the numeric ID of the root user and group is 0, not 1. The user and group with the numeric ID of 1 are usually bin, which is a system user and group that own some system binaries and directories. The bin user and group should not own the /etc/passwd file, as this would compromise the security and functionality of the system.

D. -rw------- 1 1 531 Jun 5 22:45 /etc/passwd: This option has both the wrong permissions and the wrong owner and group for the file. The permissions are 600, which means only the user can read and write the file, and the owner and group are both 1, which is the numeric ID of the bin user and group. This would prevent the system users from reading the file, and give the bin user and group full access to the file, which would cause problems for the security and functionality of the system.

The umask value that will result in the default access permissions of 600 (rw-------) for files and 700 (rwx------) for directories is 077. This is because the umask value is an octal number that represents the permissions that are not given to the files or directories. To calculate the umask value, we need to subtract the desired permissions from the maximum permissions, which are 666 for files and 777 for directories. For example, if we want the files to have the permissions 600 (rw-------), which means read and write for the owner and no permissions for the group and others, we need to subtract 600 from 666, which gives us 066. Similarly, if we want the directories to have the permissions 700 (rwx------), which means read, write, and execute for the owner and no permissions for the group and others, we need to subtract 700 from 777, which gives us 077. The umask value is the minimum of these two values, which is 077. The first digit of the umask value is for the special permissions, such as setuid, setgid, and sticky bit, and it is usually set to 0. Therefore, the final umask value is 077. For more information on how to use the umask command, you can refer to the following articles:

What Is umask in Linux, and How Do You Use It? - How-To Geek

Umask command in Linux with examples - GeeksforGeeks

What is UMASK and how to set UMASK in Linux/Unix?

How to Set and Update the Default Umask Value - phoenixNAP

A hard link is a directory entry that points to the same inode as another file. An inode is a data structure that stores the metadata and the location of the data blocks of a file. A hard link is not a separate file, but an additional name for an existing file. Therefore, the following statements are true for hard linked files:

The hard linked files have the same permissions and owner. Since the hard linked files point to the same inode, they share the same attributes, such as the file type, the file size, the access permissions, the owner, the group, and the timestamps. Any changes made to one hard link will affect the other hard links as well. For example, if you change the permissions of one hard link, the other hard links will have the same permissions. You can use the stat command to view the attributes of a file or a hard link.

The hard linked files share the same inode. This is the definition of a hard link. The inode number is a unique identifier for each file on a filesystem. The hard linked files have the same inode number, which means they point to the same data blocks on the disk. You can use the ls -i command to view the inode number of a file or a hard link.

The hard linked files must be on the same filesystem. A hard link cannot cross different filesystems or partitions, because each filesystem has its own inode table. A hard link can only point to an inode that exists on the same filesystem as the hard link. If you try to create a hard link to a file on a different filesystem, you will get an error message saying:

ln: failed to create hard link ‘link’ => ‘file’: Invalid cross-device link

The other statements are not true for hard linked files, because:

The output of stat will report hard instead of regular file. This is not true, because the stat command does not distinguish between a regular file and a hard link. The stat command will report the same file type for both the original file and the hard link, which is regular file. The only way to tell if a file is a hard link is to check the link count, which is the number of directory entries that point to the same inode. If the link count is more than one, it means there are hard links to the file. You can use the stat -c %h command to view the link count of a file or a hard link.

The hard linked files are indicated by a -> when listed with ls -l. This is not true, because the -> symbol is used to indicate a symbolic link, not a hard link. A symbolic link, also known as a soft link, is a special type of file that contains a path to another file or directory. A symbolic link does not point to the same inode as the target file, but to the name of the target file. A symbolic link has its own inode number, file type, permissions, and timestamps, which can be different from the target file. You can use the ls -l command to view the file type, permissions, and name of a file or a symbolic link. A symbolic link will have the file type l and the name will be followed by a -> symbol and the path to the target file. For example:

lrwxrwxrwx. 1 user user 9 Aug 29 15:10 link -> file

The BIOS (Basic Input/Output System) is a firmware program that is stored in a ROM chip on the motherboard, and it performs some basic tasks when the system is powered on, such as:

initializing the hardware components and peripherals

performing the power-on self-test (POST) to check the system integrity

selecting a boot device from the boot order list

loading and executing the bootloader program from the boot device

The boot device is the data carrier that contains the bootloader, which is a small program that is responsible for loading and executing the kernel. The boot device can be a hard disk, a USB drive, a CD-ROM, or a network device. The BIOS has a boot order list, which is a sequence of possible boot devices that the BIOS will search for a valid bootloader. The boot order list can be configured by the user through the BIOS setup utility, which is usually accessed by pressing a key such as F2, F10, or Del during the POST.

The BIOS will search for a bootloader by means of a special signature, which is a sequence of bytes that indicates the presence of a bootloader. The signature is usually located in the first sector of the boot device, which is called the boot sector or the master boot record (MBR). The BIOS will read the boot sector of each boot device in the boot order list, and check if the last two bytes are 0x55 and 0xAA, which are the standard boot signature. If the boot signature is found, the BIOS will load the boot sector into memory and execute it. If the boot signature is not found, the BIOS will move on to the next boot device in the boot order list. If none of the boot devices have a valid boot signature, the BIOS will display an error message such as:

No bootable device – insert boot disk and press any key

 The commands that will print important system information such as the kernel version and machine hardware architecture are uname and arch. The uname command prints system information, such as the kernel name, release, version, machine, processor, hardware platform, and operating system. The arch command prints the machine hardware name, which is equivalent to uname -m. For example, uname -a will print Linux 5.10.0-8-amd64 #1 SMP Debian 5.10.46-4 (2021-08-03) x86_64 GNU/Linux, and arch will print x86_64. The sysinfo command is not a valid Linux command. The lspci command prints information about PCI buses and devices in the system. The info command prints documentation for a given topic or command. References: LPI Exam 101 Detailed Objectives, Topic 103: GNU and Unix Commands, Weight: 25, Objective 103.1: Work on the command line, uname command, arch command, lspci command, info command