CompTIA XK0-005 Practice Test - Questions Answers, Page 21

The renice command is used to change the priority of a running process by specifying its PID and the new nice value. The -n flag indicates the amount of change in the nice value, which can be positive or negative. A lower nice value means a higher priority, so -15 will increase the priority of the process with PID 2274. The administrator needs to have root privileges to do this.

The renice command is listed as one of the commands to manipulate process priority in the web search result1.

The renice command is also explained with examples in the web search result2.

The CompTIA Linux+ Certification Exam Objectives mention that the candidate should be able to ''manage process execution priorities'' as part of the System Operation and Maintenance domain1.

The best command to use to confirm on which server the HBA card was installed is

A). lspci | egrep 'hba| fibr'. This command will list all the PCI devices on the server and filter the output for those that match the pattern 'hba' or 'fibr', which are likely to be related to the HBA card. The egrep command is a variant of grep that supports extended regular expressions, which allow the use of the '|' operator for alternation. The other commands are either invalid or will not produce the desired output. For example:

B) lspci | zgrep 'hba | fibr' will try to use zgrep, which is a command for searching compressed files, not standard output.

C) lspci | pgrep 'hba| fibr' will try to use pgrep, which is a command for finding processes by name or other attributes, not text patterns.

D) lspci | 'hba | fibr' will try to use 'hba | fibr' as a command, which is not valid and will cause an error.

The chgrp command is used to change the group ownership of files and directories. By using this command, the administrator can assign the files in the newly created directory to the human resources group, which will allow the users in that group to access them. The other commands are not relevant for this task. For example:

chattr is used to change the file attributes, such as making them immutable or append-only1.

chage is used to change the password expiration information for a user account2.

chcon is used to change the security context of files and directories, which is related to SELinux3.

The CompTIA Linux+ Certification Exam Objectives mention that the candidate should be able to ''manage file and directory ownership and permissions'' as part of the Hardware and System Configuration domain4.

The web search result2explains how to use the chgrp command with examples.

The web search result3compares the chmod and chgrp commands and their effects on file permissions.

The ssh -X option enables X11 forwarding, which allows the user to run graphical applications on the remote server and display them on the local workstation. The user needs to specify the username, the server address, and the application name after the ssh -X command. The remote server also needs to have X11Forwarding enabled and xauth installed for this to work.

The web search result8explains how to run a GUI application through SSH by configuring both the SSH client and server.

The web search result6provides a detailed answer on how to forward X over SSH to run graphics applications remotely, with examples and troubleshooting tips.

The CompTIA Linux+ Certification Exam Objectives mention that the candidate should be able to ''use SSH for remote access and management'' as part of the System Operation and Maintenance domain1.

This answer allows the accounting user to run the /opt/acc/report command as root on any host without entering a password. The % sign indicates that accounting is a group name, not a user name. The ALL keyword means any host, any user, and any command, depending on the context. The NOPASSWD tag overrides the default behavior of sudo, which is to ask for the user's password.

The other answers are incorrect for the following reasons:

A) accounting localhost=/opt/acc/report

This answer only allows the accounting user to run the command on the localhost, not on any host.

This answer also requires the accounting user to enter their password, which is not specified in the question.

B) accounting ALL=/opt/acc/report

This answer only allows the accounting user to run the command as themselves, not as root.

This answer also requires the accounting user to enter their password, which is not specified in the question.

D) accounting /opt/acc/report= (ALL) NOPASSWD: ALL

This answer has an invalid syntax, as there should be no space between the equal sign and the parentheses.

This answer also grants too much privilege to the accounting user, as it allows them to run any command as any user without a password.

The best commands to use to generate a list of rogue process names that have a TCP listener on a network interface are A. netstat -antp | grep LISTEN and B. lsof -iTCP | grep LISTEN. These commands will show the process ID (PID) and name of the processes that are listening on TCP ports, which can be used to identify any suspicious or unauthorized processes. The other commands are either not specific enough, not valid, or not relevant for this task. For example:

C) lsof -i:22 | grep TCP will only show the processes that are listening on port 22, which is typically used for SSH, and not any other ports.

D) netstat -a | grep TCP will show all the TCP connections, both active and listening, but not the process names or IDs.

E) nmap -p1-65535 | grep -i tcp will scan all the TCP ports on the local host, but not show the process names or IDs.

F) nmap -sS 0.0.0.0/0 will perform a stealth scan on the entire internet, which is not only impractical, but also illegal in some countries.

The best command to use to list all current containers, regardless of their running state, is

A) docker ps -a. This command will show all containers, both running and stopped, with details such as container ID, image name, status, and ports. The other commands are either invalid or not relevant for this task. For example:

B) docker list is not a valid command. There is no subcommand named list in docker.

C) docker image ls will list all the images available on the local system, not the containers.

D) docker inspect image will show detailed information about a specific image, not all the containers.

The best command sequence to rebuild a kernel module from source code is A. ./configure make make install. This is the standard way to compile and install a Linux kernel module, as explained in the web search result 5. The other commands are either not relevant, not valid, or not sufficient for this task. For example:

B) wget gcc cp will try to download, compile, and copy a file, but it does not specify the source code, the module name, or the destination directory.

C) tar xvzf build cp will try to extract, build, and copy a compressed file, but it does not specify the file name, the module name, or the destination directory.

D) build install configure will try to run three commands that are not defined or recognized by the Linux shell.

A long-running process is a program that takes a long time to complete or runs indefinitely on a Linux system. A foreground process is a process that runs in the current terminal and receives input from the keyboard and output to the screen. A background process is a process that runs in the background and does not interact with the terminal. A background process can continue running even if the terminal is closed or disconnected.

To start a long-running process in the background, the user can append an ampersand (&) to the command, such assomeapp &. This will runsomeappin the background and return control to the terminal immediately.

To move a long-running process from the foreground to the background, the user can use two keystrokes: Ctrl+Z and bg. The Ctrl+Z keystroke will suspend (pause) the foreground process and return control to the terminal. The bg keystroke will resume (continue) the suspended process in the background and detach it from the terminal. The statement B is correct.

The statements A, C, and D are incorrect because they do not perform the desired task. The bg keystroke alone will not work unless there is a suspended process to resume. The Ctrl+B keystroke will not suspend the foreground process, but rather move one character backward in some applications. The jobs keystroke will list all processes associated with the current terminal. The bg & keystroke will cause an error because bg does not take any arguments.Reference: [How to Run Linux Processes in Background]