LPI LPI Linux Essentials 010-160 New Questions

 The correct command to extract the contents of the compressed archive file1.tar.gz is tar -xzf file1.tar.gz. This command uses the following options:

• -x means extract files from an archive.
• -z means filter the archive through gzip, which is a compression program that reduces the size of files.
• -f means use the following archive file name, which is file1.tar.gz in this case.

The other commands are incorrect for the following reasons:

• tar -czf file1.tar.gz creates a compressed archive file1.tar.gz from the files specified after the command, not extract it.
• ztar file1.tar.gz is not a valid command, as ztar is not a standard program or option for tar.
• tar --extract file1.tar.gz is missing the -z option to handle the gzip compression, and also the -f option to specify the file name.
• detar file1.tar.gz is not a valid command, as detar is not a standard program or option for tar.

References:

• Linux Essentials - Topic 106: The Linux Operating System, section 106.2 Use single shell commands and one line command sequences to perform basic tasks on the command line.
• LPI Linux Essentials Study Guide: Exam 010 v1.6, 3rd Edition, Chapter 5: Working with Files and Directories, section Compressing and Archiving Files.

The useradd command in Linux is used to create new user accounts on the system1. The -m option tells the command to create the user’s home directory as /home/username and copy the files from /etc/skel directory to the user’s home directory2. The /etc/skel directory contains the default configuration files for new users3. Therefore, the command useradd -m tux will add the new user tux and create the user’s home directory with default configuration files. The other options are either invalid or do not create the user’s home directory. 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
• Linux useradd Command Tutorial for Beginners (15 Examples)

The /var directory must be mounted with read and write access if it resides on its own dedicated file system. The reason is that the /var directory contains files and directories that are expected to change in size and content as the normal operation of the system progresses, such as logs, spool files, and temporary files1. Therefore, the /var directory needs to have enough space and permission to accommodate these changes. If the /var directory is mounted as read-only, some system services and applications may fail to start or function properly2.

The other options are not directories that must be mounted with read and write access if they reside on their own dedicated file system. The /opt directory contains optional or third-party software packages that are not part of the default installation1. The /lib directory contains libraries and kernel modules that are essential for the binaries in /bin and /sbin directories1. The /etc directory contains configuration files for the system and applications1. The /usr directory contains user-related programs, libraries, documentation, and data1. These directories are usually mounted as read-only to prevent accidental or malicious modification of their contents3. References:

• Linux Essentials Exam Objectives, Version 1.6, Topic 102.1, Weight 3
• Linux Essentials Certification Guide, Chapter 2, Page 34-35
• Linux Filesystem Hierarchy, Chapter 3, Page 17-18

 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