CompTIA XK0-004 Pack 2021

NEW QUESTION 1
A Linux system is running normally when the systems administrator receives an alert that one application spawned many processes. The application is consuming a lot of memory, and it will soon cause the machine to become unresponsive. Which of the following commands will stop each application process?

• A. kill ‘pidof application’
• B. killall application
• C. kill -9 ‘ps –aux | grep application’
• D. pkill -9 application

Answer: B

NEW QUESTION 2
A networked has been crashing intermittently. A Linux administrator would like to write a shell script that will attempt to ping the server and email an alert if the server fails to respond. The script will later be scheduled via cron job.
Which of the following scripts would BEST accomplish this task?

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Answer: D

NEW QUESTION 3
A user wants to list the lines of a log, adding a correlative number at the beginning of each line separated by a set of dashes from the actual message. Which of the following scripts will complete this task?

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Answer: D

NEW QUESTION 4
An administrator is troubleshooting an application that has failed to start after the server was rebooted. Noticing the data volume is not mounted, the administrator attempts to mount it and receives this error:

Upon checking the logical volume status, the administrator receives this information:

Which of the following can be said about the data logical volume, and how can this problem be resolved?

• A. The logical volume is not activ
• B. The administrator should make it active with lvchange -ay /dev/ datavg/datalv and then mount it.
• C. The logical volume file system has become corrupte
• D. The administrator should repair it with xfs_repair/dev/datavg/datalv and then mount it.
• E. The logical volume is OK but the /dev special files are missin
• F. The administrator should recreate them by running /dev/MAKEDEV.
• G. The file system is read-onl
• H. The administrator should remount it as read-write with the command mount - o remount.rw /data.

Answer: A

NEW QUESTION 5
A junior Linux administrator is optimizing a system in which an application needs to take priority 0 when running the process. The administrator runs the ps command and receives the following output:

Given this scenario, which of the following steps will address this issue?

• A. Issue the command ronice –n 0 –p 8481
• B. Issue the command renice –p 8481
• C. Issue the command renice –p 0 ~n 8481
• D. Issue the command renice –n 8481

Answer: D

NEW QUESTION 6
A Linux administrator has installed a web application firewall in front of a web server running on HTTP port 8080 and successfully started the HTTP server. However, after opening the application URL in an Internet browser, the administrator discovered that the application does not work. The administrator performed the following diagnostic steps:
Output of sysctl -a command:

Output of iptables -L command:

Output of netstat –nltop | grep "8080":

Which of the following is the NEXT step the administrator should perform to permanently fix the issue at the kernel level?

• A. sysctl -w net.ipv4.ip_forward=1 then run sysctl -w /etc/sysctl.conf to enable the change
• B. Edit /etc/sysctl.conf file and add net.ipv4.ip_forward = 1 then run sysctl -p /etc/ sysctl.conf to enable the change
• C. Add iptables rule iptables -A INPUT -m state --state NEW -p tcp --dport 8080 -j then restart httpd daemon
• D. Add iptables rule iptables -A FORWARD-m state --state NEW -p tcp --dport 8080 –j ACCEPT then restart httpd daemon

Answer: D

NEW QUESTION 7
A junior administrator needs to unload an older video kernel module. Which of the following commands would BEST accomplish this task?

• A. modprobe
• B. insmod
• C. rmmod
• D. chmod

Answer: A

NEW QUESTION 8
A Linux systems administrator wants the ability to access systems remotely over SSH using RSA authentication. to which of the following files should the RSA token be added to allow this access?

• A. authorized_keys
• B. ~/.ssh/ssh_config
• C. id_rsa.pub
• D. known_hosts

Answer: C

NEW QUESTION 9
A Linux administrator has configured a Linux system to be used as a router. The administrator confirms that two network adapters are properly installed and functioning correctly. In addition, the output of the iptables –L command appears to contain a complete firewall configuration.
Which of the following commands does the administrator need to issue for the router to be fully functional?

• A. echo “1” > /proc/sys/net/ipv4/ip_forward
• B. echo “0” > /proc/sys/net/ipv4/tcp_abort_on_overflow
• C. echo “0” > /proc/sys/net/ipv4/max_connections
• D. echo “1” > /proc/sys/net/ipv4/ip_default_ttl

Answer: A

NEW QUESTION 10
A junior Linux administrator is updating local name resolution to support IPv6. The administrator issues the command cat /etc/hosts and receives the following output: 127.1.1.1 localhost
Which of the following actions should the administrator perform to accomplish this task?

• A. Modify the /etc/hosts file, and add the ipv6 localhost entry to the file.
• B. Modify the /etc/hosts file, and add the ::1 localhost entry to the file.
• C. Modify the /etc/hosts file, and add the ipv4 localhost entry to the file.
• D. Modify the /etc/hosts file, and add the 0.0.0.0 localhost entry to the file.

Answer: D

NEW QUESTION 11
A junior Linux administrator is installing a new application with CPU architecture requirements that have the following specifications:
x64 bit 3.0GHz speed
Minimum quad core
The administrator wants to leverage existing equipment but is unsure whether the requirements of these systems are adequate. The administrator issues the following command cat/proc/cpuinfo. The output of the command is as follows:

Which of the following is the recommended course of action the administrator should take based on this output?

• A. Install the application, as the system meets the application requirements
• B. Procure new equipment that matches the recommended specifications
• C. Recompile the Linux kernel to support the installation.
• D. Reconfigure lib modules to support the new application.

Answer: A

NEW QUESTION 12
A Linux administrator needs to take stock of USB devices attached to the system. Which of the following commands would be BEST to complete this task?

• A. lspci
• B. lsusb
• C. cat /proc/USB
• D. modprobe -–usb

Answer: B

NEW QUESTION 13
A user has connected a Bluetooth mouse to a computer, but it is not working properly. Which of the following commands should the systems administrator use to fix the issue?

• A. lsmod –i bluetooth
• B. insmod bluetooth
• C. modprobe –r bluetooth
• D. depmod –i bluetooth

Answer: C

NEW QUESTION 14
Ann, a junior systems administrator, is required to add a line to the /etc/yum.conf file. However, she receives the following error message when she tries to add the line:

Ann performs some diagnostics to attempt to find the root cause:

Which of the following commands should Ann execute to write content to /etc/yum?

• A. chmod 755 /etc/yum.conf
• B. setfacl –m m:rw /etc/yum.conf
• C. chattr –I /etc/yum.conf
• D. setenforce 0

Answer: A

NEW QUESTION 15
A Linux systems administrator is setting up SSH access with PKI for several using their newly created RSA keys. Which of the following MOST securely achieves this task?

• A. Use curl to copy each user’s public key file to the respective system
• B. Use cp to copy each user’s public key file to the respective system
• C. Use ssh-copy-id to copy each user’s public key file to the respective system
• D. Use ssh-copy-id to copy each user’s private key file to the respective system

Answer: C

NEW QUESTION 16
After starting a long-running script, a systems administrator needs to verify the frequency of what is filling up the /var partition and kill it because it is consuming too much space.
Which of the following is the correct sequence given only a terminal is available?

• A. 1. CTRL-C2. bg3. watch df /var4. CTRL-C5. fg6. CTRL-Z
• B. 1. CTRL-C2. fg3. watch df /var4. CTRL-Z5. bg6. CTRL-Z
• C. 1. CTRL-Z2. bg3. watch df /var4. CTRL-C5. fg6. CTRL-C
• D. 1. CTRL-Z2. bg3. watch df /var4. CTRL-Z5. fg6. CTRL-C

Answer: D

NEW QUESTION 17
A technical support engineer receives a ticket from a user who is trying to create a 1KB file in the /tmp directory and is getting the following error No space left on device. The support engineer checks the /tmp directory, and it has 20GB of free space.
Which of the following BEST describes a possible cause for this error?

• A. The /tmp directory is not mounted.
• B. The filesystem is formatted with a 4MB block size.
• C. the filesystem ran out of inodes.
• D. The /tmp directory has been set with an immutable attribute.

Answer: C

NEW QUESTION 18
A Linux administrator needs the “tech” account to have the option to run elevated commands as root. Which of the following commands would BEST meet this goal?

• A. $ su – tech –c “/bin/bash”
• B. # usermod –aG wheel tech
• C. # sudo –I tech
• D. # groupadd –u tech –g root

Answer: C

NEW QUESTION 19
A server is almost out of free memory and is becoming unresponsive. Which of the following sets of commands will BEST mitigate the issue?

• A. free, fack, partprobe
• B. lsof, lvcreate, mdadm
• C. df, du, rmmod
• D. fdisk, mkswap, swapon -a

Answer: A

NEW QUESTION 20
A Linux administrator built a GitLab server. Later that day, a software engineer tried to access the server to upload the repository during the final step of installation. The software engineer could not access the website. Which of the following firewall rules would allow access to this site?

• A. iptables –A INPUT –p tcp –m multiport --dports 80,443 –m conntrack –cstate NEW, ESTABLISHED –j ACCEPT
• B. iptables –A INPUT –p tcp –m multiport --dports 80,443 –m conntrack –cstate ESTABLISHED –j ACCEPT
• C. iptables –A INPUT –p tcp –m multiport --dports 80,443 –m conntrack –cstate RELATED, ESTABLISHED –j ACCEPT
• D. iptables –A INPUT –p tcp –m multiport --dports 80,443 –m conntrack –cstate NEW, ESTABLISHED –j REJECT

Answer: C

NEW QUESTION 21
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