010-160 Exam Dumps - LPI Linux Essentials Questions and Answers

A web server is a program that listens for requests from web browsers and serves web pages, images, or other resources. Apache HTTPD and NGINX are two popular web servers that can run on Linux systems. They can handle multiple protocols, such as HTTP, HTTPS, FTP, and SMTP. Postfix, Curl, and Dovecot are not web servers, but they are related to web or network services. Postfix is a mail transfer agent (MTA) that can send and receive emails. Curl is a command-line tool that can transfer data from or to a web server. Dovecot is a mail delivery agent (MDA) that can store and retrieve emails from a local mailbox. References:

• Linux Essentials - Linux Professional Institute (LPI), section 1.2 Major Open Source Applications
• LPI Linux Essentials 010-160 - Testprep Training Tutorials, section 4.4 Your Computer on the Network

 In an Infrastructure as a Service (IaaS) cloud, the provider offers virtualized computing resources such as servers, storage, and network over the internet. The user can provision and manage these resources according to their needs. One of the common ways to provision a new Linux computing instance in an IaaS cloud is to use a pre-prepared image of a Linux distribution provided by the cloud hosting organization. An image is a snapshot of a virtual machine that contains the operating system and other software components. The user can choose from a variety of images that suit their requirements and launch a new instance from the image. This way, the user does not have to install and configure the Linux operating system from scratch, which saves time and effort. Some examples of cloud hosting organizations that provide pre-prepared images of popular Linux distributions are Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform (GCP), and DigitalOcean. References: Linux Essentials - Topic 108: Cloud Computing and Linux Essentials - Topic 108: Cloud Computing - Exam Objectives

These are the three most common service models offered by public cloud providers12. They differ in the level of abstraction and control they provide to the customers.

• Platform as a Service (PaaS) is a service model where the public cloud provider offers a ready-to-use platform for developing, testing, and deploying applications. The provider manages the underlying infrastructure, such as servers, storage, network, and operating system, while the customer only needs to focus on the application code andconfiguration. Examples of PaaS include Google App Engine, IBM Cloud Foundry, and Microsoft Azure App Service12.
• Infrastructure as a Service (IaaS) is a service model where the public cloud provider offers access to fundamental compute, network, and storage resources on demand over the public Internet or through dedicated connections. The provider manages the physical hardware and virtualization layer, while the customer has full control over the configuration and management of the virtual machines, operating system, and applications. Examples of IaaS include Google Compute Engine, IBM Cloud Virtual Servers, and Microsoft Azure Virtual Machines12.
• Software as a Service (SaaS) is a service model where the public cloud provider offers ready-to-use software applications that run on the provider’s infrastructure and are accessible through a web browser or a mobile app. The provider manages the entire software stack, including the infrastructure, platform, and application, while the customer only needs to pay for the usage or subscription of the service. Examples of SaaS include Google Workspace, IBM Watson, and Microsoft Office 36512.

References:

• What is Public Cloud | IBM
• What Is a Public Cloud? | Google Cloud

The correct command to create an archive file work.tar from the contents of the directory ./work/ is tar –cf work.tar ./work/. This command uses the -c option to create a new archive, the -f option to specify the file name, and the ./work/ argument to indicate the source directory. The other commands are incorrect for various reasons:

• A. tar --new work.tar ./work/ is incorrect because there is no --new option in the tar command. The correct option for creating a new archive is --create or -c.
• C. tar –create work.tgz –content ./work/ is incorrect because the -content option is not valid. The correct option for specifying the source files or directories is --files-from or -T. Also, the work.tgz file name implies compression, but the command does not use any compression option such as -z, -j, or -J.
• D. tar work.tar < ./work/ is incorrect because the tar command does not accept input redirection from the standard input. The correct way to use the tar command is to provide the options and arguments after the command name.
• E. tar work > work.tar is incorrect because the tar command does not produce output redirection to the standard output. The correct way to use the tar command is to use the -f option to specify the output file name. References: : tar command in Linux with examples - GeeksforGeeks : tar Command in Linux With Examples | phoenixNAP KB

 The PATH environment variable is a colon-separated list of directories that the shell searches for commands. To add a new directory to the PATH, you need to append it to the existing value of the variable, using the syntax PATH=new/dir:PATH. However, this only changes the PATH for the current shell session. To make the change permanent, you need to use the export command, which makes the variable available to all child processes of the shell. The export command takes the name of the variable as an argument, without the dollar sign ($). Therefore, the correct command to add /new/dir/ to the PATH and export it is export PATH=/new/dir:PATH. References:

• Linux Essentials - Linux Professional Institute (LPI)
• How to set the path and environment variables in Windows - Computer Hope

The passwd command in Linux is used to change the password of a user account. A normal user can run passwd to change their own password, and a system administrator (the superuser) can use passwd to change another user’s password, or define how that account’s password can beused or changed1. The passwd command can also be used to lock or unlock a user account. Locking a user account means disabling the user’s ability to log in to the system, while unlocking a user account means restoring the user’s ability to log in. To lock a user account, the passwd command can be used with the -l option, followed by the username. To unlock a user account, the passwd command can be used with the -u option, followed by the username12. The passwd command cannot be used to change a user’s username, create a new user account, or create a new user group. These tasks require different commands, such as usermod, useradd, orgroupadd345. References: 1: Linux Passwd Command Help and Examples 2: Passwd command in Linux: 8 Practical Examples 3: usermod(8) - Linux man page 4: useradd(8) - Linux man page 5: groupadd(8) - Linux man page

A process ID on Linux is a unique integer value that identifies a running process. The process ID can range from 0 to a maximum limit, which is usually 32768 or higher, depending on the system configuration. The process ID of 0 is reserved for the kernel’s idle task, and the process ID of 1 is reserved for the init system, which is the first process launched by the kernel. The process IDs are assigned sequentially to new processes, and are recycled when a process terminates. Therefore, the only valid value for a process ID among the given options is 21398, which is an integer within the possible range. The other values are not valid process IDs because they are either strings, hexadecimal numbers, or file paths, which do not match the format of a process ID on Linux. References:

• Linux Essentials - Linux Professional Institute (LPI)
• How Are Linux PIDs Generated? | Baeldung on Linux

The correct permissions for the /tmp directory are rwxrwxrwt, which means that the owner, group, and others have read, write, and execute permissions, and that the sticky bit is set. The sticky bit is a special permission that prevents users from deleting or renaming files that they do not own in a shared directory. The /tmp directory is used for storing temporary files that may be created by different users and processes, so it needs to be accessible and writable by all, but also protected from unauthorized deletion or modification of files. The rwxrwxrwt permissions can be set by using the chmod command with either the octal mode 1777 or the symbolic mode a+trwx. References: : [File system permissions] : [Sticky bit] : [chmod]

The tar command in Linux is used to create, extract, list, and manipulate archive files1. The -c option tells the command to create a new archive file. The -f option specifies the name of the archive file. The last argument is the name of the directory or file to be archived. Therefore, the command tar -cf work.tar ./work/ will create an archive file named work.tar from the contents of the directory ./work/. The other options are either invalid or do not create the desired archive file. Option A uses an unrecognized option --new. Option C uses an incorrect option --content and an incorrect extension .tgz for a plain tar archive. Option D and E use an incorrect syntax for redirecting the input or output of the tar command. References:

• Linux Essentials Version 1.6 Objectives, Topic 1.4: Command Line Basics, Subtopic: Basic Shell Commands
• Linux Essentials Version 1.6 Exam Preparation Guide, Section 1.4: Command Line Basics, Page 16
• Tar Command in Linux (Create and Extract Archives) | Linuxize2

A symbolic link, also known as a symlink or soft link, is a special type of file that points to another file or directory by its name. A symbolic link can point to a file or directory on the same or different file system, as long as the target is accessible. For example, you can create a symbolic link to a file on a USB drive or a network share, as long as the device is mounted or the connection is established. However, if the target of the symbolic link is moved, renamed, or deleted, the link becomes broken and does not work. To create a symbolic link, you can use the ln command with the -s or --symbolic option, followed by the target name and the link name. For example, ln -s /mnt/usb/file.txt link.txt creates a symbolic link named link.txt that points to the file.txt on the USB drive mounted at /mnt/usb.

The other options are not true about links in a Linux file system. A symbolic link can point to a directory as well as a file. A hard link, which is a direct reference to the same data as another file, can only point to a file and not a directory. A hard link cannot span across different file systems, because it depends on the inode number, which is unique within a file system. When the target of the symbolic link is moved, the link is not automatically updated, but becomes broken. Any user can create hard links, as long as they have the permission to read and write the target file and the link directory.

References:

• Linux Essentials - Linux Professional Institute (LPI)
• Ln Command in Linux (Create Symbolic Links) | Linuxize