XK0-005 Exam Dumps - CompTIA Linux+ Exam

-d: run indetached(background) mode

-p 8080:80: expose port80 inside containeron8080 on host

--name myweb: sets container name

OnlyBis correctly structured.

The /etc/passwd file contains user account information, where each line includes fields separated by colons. To list all user accounts and their UIDs, use cut -d: -f1,3 /etc/passwd. This cuts the first field (username) and the third field (UID) from each line.

The ufw (Uncomplicated Firewall) delete command is used to remove rules.

If the original rule was ufw deny 80/tcp, it must be deleted with:ufw delete deny 80/tcp

If the original rule was ufw deny 80/tcp, it must be deleted with:ufw delete deny 80/tcp

If the original rule was ufw deny 80/tcp, it must be deleted with:ufw delete deny 80/tcp

Why the other options are incorrect?

A. ufw delete 80/tcp → Incorrect, because delete requires specifying the action (allow or deny).

C. ufw delete 80/tcp deny → Incorrect syntax; deny must come before the port.

D. delete7! → Incorrect, this is not a valid ufw command.

These commands can display all the firewall rules applied to the Linux servers, depending on which firewall service is being used.

The firewall-cmd command is a utility for managing firewalld, which is a dynamic firewall service that supports zones and services. The --list-all option will show all the settings and rules for the default zone, or for a specific zone if specified. For example, firewall-cmd --list-all --zone=public will show the rules for the public zone1.

The ufw command is a frontend for iptables, which is a low-level tool for manipulating netfilter, the Linux kernel’s packet filtering framework. The status option will show the status of ufw and the active rules, or the numbered rules if verbose is specified. For example, ufw status verbose will show the numbered rules and other information2.

The other options are incorrect because:

A. ufw limit

This command will limit the connection attempts to a service or port using iptables’ recent module. It does not display any firewall rules2.

B. iptables -F

This command will flush (delete) all the rules in the selected chain, or all chains if none is given. It does not display any firewall rules3.

C. systemctl status firewalld

This command will show the status of the firewalld service, including whether it is active or not, but it does not show the firewall rules4.

F. iptables -A

This command will append one or more rules to the end of the selected chain. It does not display any firewall rules3.

The command sed -i 's/auto/persistent/g' /etc/systemd/journald.conf && sed -i 'persistent/s/ˆ#//q' /etc/systemd/journald.conf will accomplish the task of guaranteeing the persistency of journal log files across system reboots. The sed command is a tool for editing text files on Linux systems. The -i option modifies the file in place. The s command substitutes one string for another. The g flag replaces all occurrences of the string. The && operator executes the second command only if the first command succeeds. The q command quits after the first match. The /etc/systemd/journald.conf file is a configuration file for the systemd-journald service, which is responsible for collecting and storing log messages. The command sed -i 's/auto/persistent/g' /etc/systemd/journald.conf will replace the word auto with the word persistent in the file. This will change the value of the Storage option, which controls where the journal log files are stored. The value auto means that the journal log files are stored in the volatile memory and are lost after reboot, while the value persistent means that the journal log files are stored in the persistent storage and are preserved across reboots. The command sed -i 'persistent/s/ˆ#//q' /etc/systemd/journald.conf will remove the # character at the beginning of the line that contains the word persistent. This will uncomment the Storage option and enable it. The command sed -i 's/auto/persistent/g' /etc/systemd/journald.conf && sed -i 'persistent/s/ˆ#//q'/etc/systemd/journald.conf will guarantee the persistency of journal log files across system reboots by changing and enabling the Storage option to persistent. This is the correct command to use to accomplish the task. The other options are incorrect because they either do not change the value of the Storage option (grep -i auto /etc/systemd/journald.conf && systemct1 restart systemd-journald.service or cat /etc/systemd/journald.conf | awk '(print $1,$3)') or do not enable the Storage option (journalctl --list-boots && systemct1 restart systemd-journald.service). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 16: Managing Logging and Monitoring, page 489.

The firewall-cmd --list-services command will return the results for which the administrator is looking. This command will list all services that are allowed through the firewall in the default zone or a specified zone. A service is a predefined set of ports and protocols that can be enabled or disabled by firewalld. The firewall-cmd --get-services command will list all available services that are supported by firewalld, not only those that are allowed through the firewall. The firewall-cmd --check-config command will check if firewalld configuration files are valid, not list services. The systemct1 status firewalld command will display information about the firewalld service unit, such as its state, PID, memory usage, and logs, not list services. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 18: Securing Linux Systems, page 543.

The docker image tag test test:v1 command can be used to assign the v1 version to the image called test. This command creates a new tag for the existing image, without changing the original image. The docker image save test test:v1 command would save the image to a file, not assign a version. The docker image build test:vl command is invalid, as vl is not a valid version number. The docker image version test:v1 command does not exist. References: [CompTIA Linux+ (XK0-005) Certification Study Guide], Chapter 16: Virtualization and Cloud Technologies, page 500.

The administrator should replace the failed drive and reconfigure the mirror to recover the volume. The LVM (Logical Volume Manager) is a tool for managing disk space on Linux systems. The LVM allows the administrator to create logical volumes that span across multiple physical volumes, such as hard disks or partitions. The LVM also supports different types of logical volumes, such as linear, striped, or mirrored. A mirrored logical volume is a type of logical volume that creates a copy of the data on another physical volume, providing redundancy and fault tolerance. The output shows that the logical volume is mirrored and that one leg of the mirror has failed due to the underlying physical volume. This means that one of the physical volumes that contains the data of the logical volume is damaged or missing. This can cause data loss and performance degradation. The administrator should replace the failed drive and reconfigure the mirror to recover the volume. The administrator should identify the failed physical volume by using commands such as pvdisplay, vgdisplay, or lvdisplay. The administrator should then remove the failed physical volume from the volume group by usingthe vgreduce command. The administrator should then install a new drive and create a new physical volume by using the pvcreate command. The administrator should then add the new physical volume to the volume group by using the vgextend command. The administrator should then reconfigure the mirror by using the lvconvert command. The administrator should replace the failed drive and reconfigure the mirror to recover the volume. This is the correct answer to the question. The other options are incorrect because they either do not recover the volume (reboot the server. The volume will automatically go back to linear mode or reboot the server. The volume will revert to stripe mode) or do not preserve the data of the volume (recreate the logical volume). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 10: Managing Storage, pages 333-334.