XK0-006 System Management Practice Test 12 — 15 Questions

Question 1

A system administrator notices that a process with PID 1234 is consuming excessive CPU. The administrator wants to terminate this process gracefully. Which command should be used?

Accepted Answer

kill 1234. The `kill` command sends SIGTERM (signal 15) by default, which requests that the process terminate gracefully — allowing it to save state, close file handles, and clean up before exiting. Since the administrator wants a graceful termination, `kill 1234` is the correct choice because it targets the specific PID with the default SIGTERM signal.

Answer

killall 1234

Answer

pkill -9 1234

Answer

kill -9 1234

Question 2

An administrator wants to start a long-running script in the background so that it continues running even after logging out. Which command should be used?

Accepted Answer

nohup script.sh &. nohup (no hangup) makes the process immune to the SIGHUP signal that is sent to child processes when the controlling terminal closes on logout. Appending & backgrounds the job so the shell returns a prompt immediately. Combining both is required: nohup alone still runs in the foreground and blocks the terminal, while & alone leaves the process vulnerable to SIGHUP on logout.

Answer

script.sh &

Answer

nohup script.sh

Answer

bg script.sh

Question 3

An administrator is troubleshooting a service that fails to start. The administrator wants to view the last 50 lines of the service's journal log entries from the current boot. Which journalctl command should be used?

Accepted Answer

journalctl -u service -b -n 50. The command journalctl -u service -b -n 50 filters by unit (-u), restricts to the current boot (-b), and shows the last 50 lines (-n 50), which exactly matches the requirement. The -b flag is the key differentiator because it limits output to the current boot session, avoiding entries from prior boots.

Answer

journalctl -f -n 50 -u service

Answer

journalctl -u service --since today

Answer

journalctl -x -n 50 -u service

Question 4

An administrator needs to apply a set of permissions to an existing directory and all its contents, setting the owner to 'rwx', group to 'rx', and others to '---'. Additionally, newly created files within the directory should inherit the group. Which commands should the administrator run? (Assume the directory is /data, and the group is 'staff'.)

Accepted Answer

chmod -R 750 /data; chmod g+s /data. The command 'chmod -R 750 /data' recursively sets permissions for the directory and all its contents to owner rwx, group rx, and others none. The command 'chmod g+s /data' sets the setgid bit on the directory, ensuring that newly created files and subdirectories inherit the group ownership of the directory (staff). Together, these commands meet the requirements.

Answer

chmod 750 /data; chmod g+s /data

Answer

chmod -R 755 /data; chmod g+s /data

Answer

chmod -R 750 /data

Question 5

A technician needs to create a new ext4 filesystem on /dev/sdb1 and mount it persistently at /mnt/data. Which set of commands accomplishes this?

Accepted Answer

mkfs -t ext4 /dev/sdb1; mount /dev/sdb1 /mnt/data; echo '/dev/sdb1 /mnt/data ext4 defaults 0 2' >> /etc/fstab. The correct sequence must (1) create the filesystem with mkfs, (2) mount it now so it is usable immediately, and (3) add an /etc/fstab entry so the mount persists across reboots. Option A does all three in the right order using mkfs -t ext4, mount, and an fstab line with dump=0 and fsck pass=2. The fsck pass value of 2 is appropriate for a non-root filesystem.

Answer

mkfs.ext4 /dev/sdb1; echo '/dev/sdb1 /mnt/data ext4 defaults 0 2' >> /etc/fstab

Answer

mkfs.ext4 /dev/sdb1; mount /dev/sdb1 /mnt/data

Answer

echo '/dev/sdb1 /mnt/data ext4 defaults 0 2' >> /etc/fstab; mount -a

Answer

fdisk /dev/sdb1; mount /dev/sdb1 /mnt/data; echo '/dev/sdb1 /mnt/data ext4 defaults 0 2' >> /etc/fstab

Question 6

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. Both ps aux (C) and ps -ef (E) are correct because the ps command with these option sets lists every process on the system, not just the current user's, and includes the full command line for each process. ps aux uses BSD-style syntax where 'a' shows processes from all users, 'u' displays user-oriented format, and 'x' includes processes without a controlling terminal, with the COMMAND column showing the full command line. ps -ef uses UNIX-style syntax where '-e' selects all processes and '-f' produces full-format output including UID, PID, PPID, and the complete command line. pstree (A) only shows processes as a hierarchical tree and does not display full command lines with arguments. top (B) and htop (D) are interactive process viewers that by default show only a truncated command column and are not the standard non-interactive way to list all processes with full command lines.

Answer

pstree

Answer

top

Answer

htop

Question 7

An administrator needs to update the package cache and upgrade all installed packages on a Debian-based system. Which TWO commands are appropriate for this task? (Select TWO.)

Accepted Answer

apt update. Option B, `apt update`, is correct because it refreshes the local package index/cache from the repositories configured in /etc/apt/sources.list and sources.list.d, which is the required first step before any upgrade so APT knows the latest available versions. Option C, `apt upgrade`, is correct because it installs the newest versions of all currently installed packages using the refreshed cache, while safely holding back packages that would require removing or adding other packages. Together, `apt update` followed by `apt upgrade` accomplishes updating the package cache and upgrading installed packages on a Debian-based system. Option A, `apt dist-upgrade`, is not one of the marked answers here; it performs a more aggressive upgrade that can add or remove packages to resolve dependencies, which goes beyond the stated task. Option D, `dpkg --configure -a`, only reconfigures packages left unconfigured after an interrupted installation and does not update the cache or upgrade packages. Option E, `apt list --upgradable`, merely lists packages with available upgrades and performs no cache refresh or installation.

Answer

apt dist-upgrade

Answer

dpkg --configure -a

Answer

apt list --upgradable

Question 8

A Linux administrator needs to view the contents of a compressed log file without decompressing it. Which command should be used?

Accepted Answer

zcat. zcat is the correct command because it decompresses and displays the contents of files compressed with gzip (or compress) to standard output without creating a decompressed file on disk. This allows viewing compressed logs directly, which is essential for troubleshooting without modifying the original file. It is functionally equivalent to 'gzip -dc' or 'gunzip -c'.

Answer

cat

Answer

bzcat

Answer

gunzip

Question 9

An administrator runs the command `ls -l file.txt` and sees the permissions `-rwsr-xr-x`. What special permission is set on this file?

Accepted Answer

SUID. The 's' in the owner execute position indicates the SUID (Set User ID) permission is set.

Answer

SGID

Answer

Sticky bit

Answer

No special permission

Question 10

Which directory in the Filesystem Hierarchy Standard (FHS) contains variable data such as logs and spool files?

Accepted Answer

/var. /var is the correct directory because the Filesystem Hierarchy Standard (FHS) designates /var for variable data files that are expected to change in size and content as the system runs, such as logs, spool files, and temporary files. This includes /var/log for system logs and /var/spool for print and mail queues. It is distinct from static data like binaries or configuration.

Answer

/opt

Answer

/etc

Answer

/tmp

Question 11

An administrator needs to give a user read and write access to a file without changing the file's group or adding the user to any group. Which method should be used?

Accepted Answer

setfacl -m u:username:rw file. Access Control Lists (ACLs) allow granting permissions to specific users or groups beyond the traditional owner/group/other model. The command 'setfacl -m u:username:rw file' adds a named user entry to the file's ACL, giving that user read and write access without altering the file's group ownership or requiring group membership changes. This is the standard Linux method for per-user granular permissions.

Answer

chown user: file

Answer

chmod u+rw file

Answer

chgrp to user's primary group

Question 12

A process is consuming excessive CPU and needs to be stopped immediately. The process ID is 4582. Which command should be used?

Accepted Answer

kill -9 4582. The `kill -9 4582` command sends SIGKILL (signal 9) to process ID 4582, which forcibly terminates the process immediately without allowing it to clean up. This is the correct choice when a process is consuming excessive CPU and must be stopped immediately, as SIGKILL cannot be caught or ignored.

Answer

kill -1 4582

Answer

kill -STOP 4582

Answer

kill -15 4582

Question 13

An administrator wants to ensure a service starts automatically at boot on a systemd-based system. Which command should be used?

Accepted Answer

systemctl enable service. On systemd-based systems, 'systemctl enable <service>' creates the necessary symlinks (typically in /etc/systemd/system/) so that the service is started automatically at boot. It does not start the service immediately; it only configures it for future boots.

Answer

systemctl start service

Answer

systemctl status service

Answer

systemctl reload service

Question 14

A technician needs to check which package provides the file /usr/bin/foo on a CentOS 8 system. Which command should be used?

Accepted Answer

rpm -qf /usr/bin/foo. On RPM-based systems, rpm -qf queries the package that owns a given file.

Answer

rpm -V /usr/bin/foo

Answer

rpm -qi /usr/bin/foo

Answer

rpm -ql /usr/bin/foo

Question 15

Which command creates a symbolic link named 'link.txt' that points to 'original.txt'?

Accepted Answer

ln -s original.txt link.txt. ln -s target link_name creates a symbolic link.

Answer

symlink original.txt link.txt

Answer

ln original.txt link.txt

Answer

ln -s link.txt original.txt