CompTIA XK0-005 Online Practice Questions and Exam Preparation

CompTIA XK0-005 Online Questions & Answers

• Question 31:

  Users are reporting that a production application has slow performance. A systems administrator logs in to the server and performs some basic checks. Given the following: yaml [root@comptia]# ps -o pcpu; pidstat 1 Average: UID PID %usr %system %wait %CPU Command Average: 0 937242 32.39 0 63.21 32.39 app_prd Average: 0 937245 44.97 0.31 51.57 45.28 app_prd Average: 0 937244 23.62 0 63.55 28.62 app_prd [root@comptia]# vmstat 1

  procs memory swap io system cpu r b swpd free buff cache si so bi bo in cs us sy id wa st 16 0 978912 376320 50804 10296312 0 0 0 44 5503 2962 98 2 0 0 0 [root@comptia]# free -m total used free shared buff/cache available Mem: 15533 5063 365 164 10104 9975 Swap: 7931 955 6976 Which of the following is causing the performance issue?

  A. The server does not have enough memory
  B. Too many processes are running on the server
  C. The server CPU is receiving too much load
  D. The server is swapping
  D. The server is swapping

  ---

  Explanation

  The output from free -m shows that a significant portion of the swap space (955 MB) is being used, indicating the server is swapping. Swapping occurs when the system runs low on physical memory, leading to poor performance because the system must offload memory pages to the slower swap space. To resolve this, either more physical memory should be added or the application's memory usage should be optimized.

• Question 32:

  An administrator is troubleshooting a database service outage that was reported by a monitoring system. Given the following output: $ systemctl status mariadb Oct 20 16:40:45 comptia systemd[1]: mariadb.service: Main process exited, code=killed, status=9/KILL Oct 20 16:40:45 comptia systemd[1]: mariadb.service: Failed with result 'signal'. Oct 20 16:40:50 comptia systemd[1]: Stopped MariaDB 10.3 database server. $ dmesg [ 1061.491433] oom

  kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_o om, task_memcg=/system.slice/mariadb.service, task=mysqld,pid=1981,uid=27 [ 1061.491453] Out of memory: Killed process 1981 (mysqld) total-vm:330668kB, anon- rss:31316kB, file-rss:OkB, shmem-rss:OkB, UID:27 pgtables:324kB oom_score_adj:0 Which of the following is the reason for the outage?

  A. The administrator sent a kill signal to the database
  B. The server is missing the DMA bus
  C. The database cannot write anything else to the storage
  D. The server does not have enough physical memory
  D. The server does not have enough physical memory

  ---

  Explanation

  The oom-killer was invoked because the system ran out of memory, and as a result, it killed the mysqld process to free memory. This is a clear indication that the server did not have enough physical memory to run the MariaDB service, leading to the process being terminated.

• Question 33:

  When trying to log in remotely to a server, a user receives the following message:

  

  The server administrator is investigating the issue on the server and receives the following outputs:

  

  Which of the following is causing the issue?

  A. The wrong permissions are on the user's home directory.
  B. The account was locked out due to three failed logins.
  C. The user entered the wrong password.
  D. The user has the wrong shell assigned to the account.
  D. The user has the wrong shell assigned to the account.

  ---

  Explanation

  The user has the wrong shell assigned to the account, which is causing the issue. The output 1 shows that the user's shell is set to /bin/false, which is not a valid shell and will prevent the user from logging in. The output 2 shows that the user's home directory has the correct permissions (drwxr-xr-x), and the output 3 shows that the user entered the correct password and was accepted by the SSH daemon, but the session was closed immediately due to the invalid shell. The other options are incorrect because they are not supported by the outputs.

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 13: Managing Network Services, page 413.

• Question 34:

  Users in the human resources department are trying to access files in a newly created directory. Which of the following commands will allow the users access to the files?

  A. chattr
  B. chgrp
  C. chage
  D. chcon
  B. chgrp

  ---

  Explanation

  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.

  References:

  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 result 2 explains how to use the chgrp command with examples. The web search result 3 compares the chmod and chgrp commands and their effects on file permissions.

• Question 35:

  A Linux administrator is troubleshooting an SSHD issue on a server. Users are receiving error messages stating the connection is refused. Which of the following commands should be used to verify whether the service is listening?

  A. nslookup
  B. route
  C. netstat
  D. ifconfig
  C. netstat

  ---

  Explanation

  netstat is a command-line tool that displays network connections, routing tables, and a number of network interface statistics. It can be used to check if the SSHD service is listening on its default port (usually port 22) or any other configured port.

• Question 36:

  DRAG DROP

  You have been asked to parse a log file of logins to determine various information about who is logging in and when.

  INSTRUCTIONS

  Open and inspect the Login log file.

  Drag and drop the correct commands onto the output that was generated from that command.

  Tokens can be used only once and not all will be used.

  If at any time you would like to bring back the initial state of the simulation, please click the Reset All button.

  Select and Place:

  

  

• Question 37:

  A security analyst is monitoring the network to identify latency or slowdowns during a vulnerability scan. Which of the following functions will best achieve this?

  bash

  function x() {

  info=$(ping -c 1 $1 | awk -F "/" 'END {print $5}')

  echo "$1 | $info"

  }

  A. function x() { info=$(dig $(dig -x $1 | grep ptr | tail -n 1 | awk -F ".in-addr" '{print $1}').origin.asn.cymru.com TXT +short); echo "$1 | $info" }
  B. function x() { info=$(ping -c 1 $1 | awk -F "/" 'END {print $5}'); echo "$1 | $info" }
  C. function x() { info=$(nc -m 40 $1 | awk 'END {print $1}'); echo "$1 | $info" }
  D. function x() { info=$(geoiplookup $1); echo "$1 | $info" }
  B. function x() { info=$(ping -c 1 $1 | awk -F "/" 'END {print $5}'); echo "$1 | $info" }

  ---

  Explanation

  The ping command is used to measure network latency. The function provided uses ping -c 1 to ping the target once and extracts the average round-trip time using awk. This is a simple and effective way to monitor network latency during a scan or other network activity.

• Question 38:

  A Linux administrator is working with a CPU-intensive program called data-analysis. The administrator needs to prevent the program from monopolizing CPU resources and ensure that other critical processes are not impacted when the program starts. Which of the following commands would start the program with a reduced level of impact to the system?

  A. data-analysis1 --nice 15
  B. nice data-analysis1
  C. nice -15 data-analysis1
  D. data-analysis1 and nice +5
  B. nice data-analysis1

  ---

  Explanation

• Question 39:

  A Linux administrator is tasked with creating resources using containerization. When deciding how to create this type of deployment, the administrator identifies some key features, including portability, high availability, and scalability in production. Which of the following should the Linux administrator choose for the new design?

  A. Docker
  B. On-premises systems
  C. Cloud-based systems
  D. Kubernetes
  D. Kubernetes

  ---

  Explanation

  The Linux administrator should choose Kubernetes for the new design that requires portability, high availability, and scalability in production using containerization. Kubernetes is an open-source platform that automates the deployment, scaling, and management of containerized applications across clusters of nodes. Kubernetes provides features such as service discovery, load balancing, storage orchestration, self-healing, secret and configuration management, and batch execution. Kubernetes also supports multiple container runtimes, such as Docker, containerd, and CRI-O, making it portable across different platforms and clouds.

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter

  18: Automating Tasks; What is Kubernetes? | Kubernetes

• Question 40:

  An administrator is running a web server in a container named WEB, but none of the error output is showing. Which of the following should the administrator use to generate the errors on the container?

  A. docker-compose inspect WEB
  B. docker logs WEB
  C. docker run --name WEB --volume /dev/stdout:/var/log/nginx/error.log
  D. docker ps WEB -f
  B. docker logs WEB

  ---

  Explanation

  The docker logs command retrieves logs, including errors, for a running container. By using docker logs WEB, the administrator can check the error output generated by the web server container and debug any issues related to application performance or errors.