XK0-006 Practice Test 48 — 15 Questions

Question 1

A Linux administrator wants to prevent users from reusing their last five passwords. Which PAM module should be configured?

Accepted Answer

pam_pwhistory. The pam_pwhistory module is specifically designed to enforce password history policies by storing a user's previous passwords in a separate file (e.g., /etc/security/opasswd) and preventing reuse of those passwords. By configuring the 'remember' option in the PAM stack, the administrator can set the number of previous passwords that cannot be reused, such as 'remember=5' to block the last five passwords.

Answer

pam_faillock

Answer

pam_pwquality

Answer

pam_unix

Question 2

Match each Linux access control mechanism to its description.

Accepted Answer

DAC: File owners set permissions for their own files.. Correct matches: DAC relates to owner-set permissions; MAC involves system-wide policy enforcement; RBAC uses roles; ACLs extend permissions to multiple users/groups. Common confusions include swapping DAC and MAC definitions, or confusing DAC with RBAC.

Answer

DAC: Access is granted based on user roles.

Answer

MAC: File owners set permissions for their own files.

Question 3

A system administrator needs to set the umask so that newly created files have permissions of 644 and directories have permissions of 755. Which umask value should be set?

Accepted Answer

0022. Default base permissions are 666 for files and 777 for directories. To get 644 (rw-r--r--) for files: 666 - 644 = 022. To get 755 (rwxr-xr-x) for directories: 777 - 755 = 022. So umask 022 works for both.

Answer

0222

Answer

000

Answer

077

Question 4

A technician needs to kill a process with PID 1234 that is not responding to normal termination. Which command sends SIGKILL?

Accepted Answer

kill -9 1234. kill -9 sends SIGKILL, which forcefully terminates the process.

Answer

kill 1234

Answer

kill -15 1234

Answer

kill -1 1234

Question 5

An administrator wants to find all files in /var/log that have been modified within the last 2 days and have a .log extension. Which command should be used?

Accepted Answer

find /var/log -type f -mtime -2 -name "*.log". The find command with -mtime -2 finds files modified less than 2 days ago, and -name '*.log' matches the extension.

Answer

find /var/log -mtime 2 -name *.log

Answer

locate --mtime -2 *.log /var/log

Answer

ls -la /var/log | grep "\.log$" | head -20

Question 6

A Linux administrator needs to view the last 10 lines of a log file named 'syslog'. Which command should be used?

Accepted Answer

tail -10 syslog. The 'tail' command outputs the last lines of a file; by default it shows 10 lines.

Answer

cat syslog

Answer

head -10 syslog

Answer

less syslog

Question 7

An administrator notices that a service named 'httpd' is not running. They want to check its current status and, if inactive, start it. Which set of systemctl commands should be used?

Accepted Answer

systemctl status httpd; if inactive, systemctl start httpd. systemctl status httpd shows the status; if inactive, systemctl start httpd starts it. The other options have incorrect commands or syntax.

Answer

systemctl list-units httpd; if inactive, systemctl run httpd

Answer

systemctl show httpd; if inactive, systemctl launch httpd

Answer

systemctl is-active httpd; if inactive, systemctl enable httpd

Question 8

A process with PID 2345 is not responding. The administrator wants to force stop the process immediately. Which command should be used?

Accepted Answer

kill -9 2345. SIGKILL (signal 9) forcefully terminates a process. kill -9 2345 sends SIGKILL to PID 2345.

Answer

kill -1 2345

Answer

pkill -15 -f processname

Answer

kill -15 2345

Question 9

A system administrator wants to change the priority of a running process with PID 1234 to a lower priority (higher nice value). Which command should be used?

Accepted Answer

renice -n 10 -p 1234. renice is used to change the nice value of an existing process. A higher nice value means lower priority.

Answer

renice -n -10 -p 1234

Answer

chrt -p 10 1234

Answer

nice -n 10 -p 1234

Question 10

Which directory in the Linux filesystem contains essential user command binaries that are needed for booting and repairing the system?

Accepted Answer

/bin. /bin contains essential command binaries required for booting and recovery.

Answer

/usr/bin

Answer

/sbin

Answer

/opt

Question 11

Which command is used to create a symbolic link named 'link' pointing to the file 'original'?

Accepted Answer

ln -s original link. ln -s creates a symbolic link.

Answer

symlink original link

Answer

ln -s link original

Answer

ln original link

Question 12

An administrator wants to list all files in the current directory that are larger than 1 MB. Which find commands are correct? (Choose two.)

Accepted Answer

find . -type f -size +1M. Both options A and D are syntactically correct and will produce the same result. The find command evaluates expressions in order, but the -type and -size conditions are independent; their order does not affect functionality. Option A (find . -type f -size +1M) specifies file type before size, while option D (find . -size +1M -type f) specifies size before file type. Both are valid because find processes predicates left-to-right, but since -type f filters by file type and -size +1M filters by size, any file that does not satisfy both will be excluded regardless of order.

Answer

find . -type f -size 1M

Answer

find . -type f -size +1MB

Question 13

A user wants to create a hard link to a file. Which three conditions must be true for a hard link to be created successfully? (Choose three.)

Accepted Answer

The source and link must be on the same filesystem.. Hard links cannot span filesystems, cannot link to directories (except by root with special options), and the target must exist. They share the same inode.

Answer

The source file must have the SUID bit set.

Answer

The link must have the same name as the source.

Question 14

An administrator needs to replace all occurrences of 'oldhost' with 'newhost' in the file /etc/hosts. Which sed command should be used?

Accepted Answer

sed -i 's/oldhost/newhost/g' /etc/hosts. sed -i 's/oldhost/newhost/g' /etc/hosts performs an in-place substitution globally.

Answer

sed -e 's/oldhost/newhost/' /etc/hosts

Answer

sed -n 's/oldhost/newhost/gp' /etc/hosts

Answer

sed 's/oldhost/newhost/' /etc/hosts

Question 15

A user wants to create a hard link named 'linkfile' to an existing file 'original'. Which command accomplishes this?

Accepted Answer

ln original linkfile. The ln command without -s creates a hard link. ln -s creates a symbolic link. cp copies the file; mv moves it.

Answer

mv original linkfile

Answer

ln -s original linkfile

Answer

cp original linkfile