XK0-006 Practice Test 21 — 15 Questions

Question 1

A Linux engineer is troubleshooting a boot issue. The system boots to a command-line interface but does not start the graphical interface. Which systemd target should be set as default to boot into a graphical environment?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

graphical.target. graphical.target is the systemd target for a graphical user interface.

Answer

emergency.target

Answer

rescue.target

Answer

multi-user.target

Question 2

A Linux administrator wants to search for all occurrences of the word 'ERROR' in log files under /var/log, ignoring case, and also print the line numbers. Which command should be used?

Accepted Answer

grep -rin 'ERROR' /var/log. grep -rin 'ERROR' /var/log searches recursively, ignores case, and prints line numbers. -i for case-insensitive, -n for line numbers, -r for recursive.

Answer

grep -vi 'ERROR' /var/log

Answer

grep -rn 'ERROR' /var/log

Answer

find /var/log -name '*ERROR*'

Question 3

A Linux administrator wants to search for the pattern 'ERROR' in all files under /var/log, ignoring case, and display line numbers. Which THREE options should be used with the grep command? (Select THREE).

Accepted Answer

-i. grep -r for recursive, -i for case-insensitive, -n for line numbers.

Answer

-c

Answer

-v

Question 4

An administrator suspects that a malicious process is running and wants to list all processes, including those without a controlling terminal, and see their full command line. Which two commands can provide this information? (Select TWO.)

Accepted Answer

ps aux. ps aux shows all users, all processes, including those without tty, and includes the full command line. ps -ef also shows full listing with command line.

Answer

lsof

Answer

ps -eo pid,cmd

Answer

top -b -n 1

Question 5

A user reports that a script in /home/user/script.sh fails to execute. The output of 'ls -l script.sh' is '-rw-r--r-- 1 user user 1024 Apr 1 10:00 script.sh'. Which command should be used to make the script executable for all users?

Accepted Answer

chmod a+x script.sh. The file is currently not executable (rw-r--r--). To add execute permission for all users, use chmod a+x or chmod +x.

Answer

chmod 644 script.sh

Answer

chmod u+x script.sh

Answer

chmod 755 script.sh

Question 6

Given an ACL entry 'u:john:rwx' on a file, which command would remove only the ACL entry for user john without affecting other ACL entries?

Accepted Answer

setfacl -x u:john /path/to/file. setfacl -x removes a specific ACL entry. The syntax 'u:john' removes the ACL for user john.

Answer

setfacl -k /path/to/file

Answer

setfacl -m u:john:- /path/to/file

Answer

setfacl -b /path/to/file

Question 7

A Linux administrator needs to change the permissions of a file to be readable and writable by the owner, readable by the group, and no access for others. Which command accomplishes this?

Accepted Answer

chmod 640 file. The octal representation 640 sets owner read/write (6), group read (4), and others none (0).

Answer

chmod 600 file

Answer

chmod 664 file

Answer

chmod 644 file

Question 8

A system administrator wants to ensure that a service starts automatically at boot time using systemd. Which command should be used?

Accepted Answer

systemctl enable service. systemctl enable creates symlinks to make the service start at boot.

Answer

systemctl start service

Answer

systemctl daemon-reload

Answer

systemctl reenable service

Question 9

A system administrator wants to display a list of all currently running processes, including those of other users, with full command lines. Which TWO commands can achieve this? (Select TWO.)

Accepted Answer

ps aux. ps aux and ps -ef both show all processes with full command lines. top and htop show dynamic views but not in a static list format. pstree shows process tree.

Answer

pstree

Answer

top

Answer

htop

Question 10

An administrator needs to view the last 20 lines of the systemd journal for the 'sshd' service. Which command should be used?

Accepted Answer

journalctl -u sshd -n 20. journalctl -u sshd -n 20 shows the last 20 lines of the journal for the sshd unit.

Answer

systemctl status sshd | tail -20

Answer

journalctl -u sshd --since '1 hour ago'

Answer

journalctl -u sshd -f

Question 11

A Linux administrator needs to add an ACL entry to grant read permission to a user named 'jdoe' on a file. Which TWO commands can be used to achieve this? (Select TWO).

Accepted Answer

setfacl -m u:jdoe:r file. Both setfacl -m and setfacl --modify can be used to modify ACLs. The -m option is the short form, and --modify is the long form.

Answer

chown jdoe file

Answer

setfacl -x u:jdoe file

Answer

chmod u+r file

Question 12

Which command is used to display the contents of a compressed log file without decompressing it?

Accepted Answer

zcat. zcat is used to view compressed files; it is equivalent to gunzip -c.

Answer

head

Answer

cat

Answer

less

Question 13

Which command is used to display the current process hierarchy in a tree format?

Accepted Answer

pstree. ps aux shows all processes with details, but pstree shows them in a tree format, which is useful for visualizing parent-child relationships.

Answer

lsproc

Answer

ps aux

Answer

top

Question 14

A system administrator needs to remove all files in /tmp that have not been accessed in the last 30 days and are not owned by root. Which two commands, combined, could be used to accomplish this? (Select TWO).

Accepted Answer

find /tmp -atime +30 -not -user root -delete. find with -atime and -not -user root locates files; then use -exec rm or -delete to remove.

Answer

find /tmp -mtime +30 -not -user root -delete

Answer

find /tmp -atime -30 -user root -delete

Answer

find /tmp -atime +30 -user root -exec rm {} \;

Question 15

A system administrator wants to create a bind mount in Docker to share a host directory `/data` with a container at `/mnt/data`. Which of the following docker run options should be used?

Accepted Answer

-v /data:/mnt/data. Bind mounts are specified with -v or --mount. The -v syntax is host-path:container-path.

Answer

--mount type=volume,source=/data,target=/mnt/data

Answer

-v /data:ro

Answer

-v /mnt/data:/data