XK0-006 System Management Practice Test 4 — 15 Questions

Question 1

A technician needs to apply an access control list (ACL) to a file to grant read and write permissions to a specific user. Which two commands are used to manage ACLs? (Choose two.)

Accepted Answer

setfacl. Option D, setfacl, is correct because it is the command used to set or modify POSIX ACL entries on a file, such as granting a specific user read and write permissions with a syntax like setfacl -m u:username:rw file. Option E, getfacl, is correct because it is the companion command that displays the existing ACL entries of a file, allowing the technician to verify the permissions that were applied. Together, setfacl and getfacl are the standard utilities for managing and inspecting file ACLs on Linux systems. Option A, chmod, only changes the traditional owner/group/other permission bits and cannot grant permissions to an arbitrary specific user. Option B, chown, only changes file ownership (user and/or group) and does not manage ACL entries. Option C, umask, only sets default permission masks for newly created files and does not apply ACLs to an existing file.

Answer

chmod

Answer

chown

Answer

umask

Question 2

An administrator needs to permanently disable a systemd service from starting at boot. Which two commands can achieve this? (Choose two.)

Accepted Answer

systemctl disable servicename. Option C, systemctl disable servicename, is correct because it removes the symlinks in the systemd unit's .wants/ directories (e.g., under /etc/systemd/system/multi-user.target.wants/), which prevents the service from being started automatically at boot. Option E, systemctl mask servicename, is correct because it symlinks the unit file to /dev/null, making the service impossible to start either manually or as a dependency, which permanently prevents it from starting at boot. Option A, systemctl stop servicename, only halts the running service immediately and does not affect boot-time activation. Option B, systemctl kill servicename, merely sends a signal to the service's processes and has no bearing on boot behavior. Option D, systemctl unmask servicename, does the opposite of masking by removing the /dev/null symlink, so it would re-enable the unit rather than disable it.

Answer

systemctl stop servicename

Answer

systemctl kill servicename

Answer

systemctl unmask servicename

Question 3

A Linux administrator is investigating a performance issue on a server. The administrator needs to identify which processes are consuming the most CPU and memory, and then adjust their priority. Which TWO commands should the administrator use to accomplish this? (Choose TWO.)

Accepted Answer

top. Option C, top, is correct because it provides a real-time, dynamically refreshing view of running processes sorted by CPU and memory usage, allowing the administrator to identify the top consumers interactively. Option E, renice, is correct because it changes the nice value (priority) of an already running process, which is exactly what is needed to adjust priority after identifying the offending processes. The kill command (A) only sends signals to terminate or otherwise signal processes and does not display resource usage or adjust priority. The ps command (B) shows a static snapshot of processes and can display CPU/memory usage, but it cannot adjust priority. The nice command (D) only sets the priority when launching a new process, not for already running processes that the administrator has identified.

Answer

kill

Answer

ps

Answer

nice

Question 4

A system administrator needs to locate all regular files in /var/log that have been modified within the last 7 days and have a size greater than 10 MB. The administrator then needs to compress these files using gzip. Which THREE commands or options should be used together to accomplish this? (Choose THREE.)

Accepted Answer

find. Option A, find, is correct because find is the standard tool for traversing a directory tree and filtering entries by attributes such as file type, modification time, and size, which is exactly what this scenario requires. Option C, gzip, is correct because gzip is the compression utility needed to compress the located files, replacing each with a .gz archive. Option D is correct because the command find /var/log -type f -mtime -7 -size +10M -exec gzip {} \; precisely implements the requirements: -type f restricts results to regular files, -mtime -7 selects files modified within the last 7 days, -size +10M selects files larger than 10 MB, and -exec gzip {} \; compresses each matching file. Option B, locate, is not correct because it relies on a prebuilt mlocate database and cannot filter by modification time or size, nor does it guarantee current results. Option E, xargs, is not correct because although it can pipe filenames to gzip, it is not required here since find's -exec action already performs the compression directly, and xargs alone cannot locate or filter the files.

Answer

locate

Answer

xargs

Question 5

A Linux administrator is configuring file permissions for a shared directory used by a development team. The administrator wants to ensure that any new files created in the directory inherit the group ownership of the directory and that the group has read and write permissions on those files. Which TWO actions should the administrator take? (Choose TWO.)

Accepted Answer

Use the command 'chmod g+s /shared' to set the SGID bit on the directory.. Option A is correct because setting the SGID bit with 'chmod g+s /shared' causes new files and subdirectories created inside /shared to inherit the directory's group ownership rather than the creator's primary group, which is exactly the group-ownership inheritance the administrator wants. Option E is correct because 'setfacl -d -m g:devteam:rw /shared' installs a default ACL on the directory, and default ACLs are inherited by newly created files and subdirectories, granting the devteam group read and write permissions on those new files. Option B is wrong because a non-default ACL on /shared only affects access to the directory itself, not permissions on files created within it. Option C is wrong because 'chmod 2770' sets SGID and rwx for owner and group on the directory, but it does not control the permissions of newly created files, so it does not satisfy the read/write inheritance requirement. Option D is wrong because 'umask 0007' is not a valid way to set a directory-specific umask and would not reliably produce the required group read/write inheritance for new files.

Answer

Use the command 'setfacl -m g:devteam:rw /shared' to set an ACL on the directory.

Answer

Use the command 'chmod 2770 /shared' to set permissions with SGID and full access for owner and group.

Answer

Use the command 'umask 0007' to set the umask for the directory.

Question 6

A Linux administrator needs to schedule a one-time job that will run at 2:30 AM tomorrow. The job should execute a script located at /home/user/backup.sh. Which command should the administrator use to schedule this job?

Accepted Answer

echo '/home/user/backup.sh' | at 2:30 AM tomorrow. The at command is specifically designed for one-time scheduled tasks. Piping the script path into at schedules it to run at the specified time. The crontab is for recurring jobs, systemd-run creates transient units that may recur, and the at command with -f is not valid syntax.

Answer

crontab -e and add the line '30 2 * * * /home/user/backup.sh'

Answer

at 2:30 AM tomorrow -f /home/user/backup.sh

Answer

systemd-run --on-calendar='*-*-* 02:30:00' /home/user/backup.sh

Question 7

A Linux administrator needs to configure a systemd service to start automatically only when the system reaches the graphical.target, and not during multi-user.target. Which command should be used to set this dependency?

Accepted Answer

systemctl add-wants graphical.target myservice.service. To make a service start when a specific target is reached, you create a dependency from that target to the service. The 'systemctl add-wants' command adds a Wants dependency, ensuring the service is started when the target is activated. This is the correct method to tie a service to graphical.target without making it a requirement of the boot process.

Answer

systemctl enable graphical.target

Answer

systemctl isolate graphical.target

Answer

systemctl set-default graphical.target

Question 8

A Linux administrator is troubleshooting a server that fails to boot, dropping into an emergency shell. The root filesystem is mounted read-only. The administrator needs to remount the root filesystem with read-write permissions to make repairs. Which command should be used?

Accepted Answer

mount -o remount,rw /. To remount the root filesystem as read-write in an emergency shell, the mount command with the remount,rw options is used. This is a common step during system recovery. Other options either perform unrelated actions or are unsafe on a mounted filesystem.

Answer

mount -o rw /dev/sda1 /mnt

Answer

systemctl daemon-reload

Answer

fsck -y /

Question 9

A Linux administrator needs to schedule a recurring backup script to run every day at 2:00 AM. The script is located at /usr/local/bin/backup.sh and must run as the user 'backupuser'. Which two methods can be used to achieve this? (Choose two.)

Accepted Answer

Add a line to /etc/crontab: 0 2 * * * backupuser /usr/local/bin/backup.sh. System-wide cron jobs that require a specific user can be defined in /etc/crontab or in a file under /etc/cron.d/, both of which include a username field. These methods allow the administrator to schedule the backup script to run as 'backupuser' at the specified time.

Answer

Run crontab -e as backupuser and add: 0 2 * * * /usr/local/bin/backup.sh

Answer

Add a line to /etc/cron.daily/backup: 0 2 * * * backupuser /usr/local/bin/backup.sh

Answer

Use systemd timer with OnCalendar=*-*-* 02:00:00 and User=backupuser in the service unit

Question 10

A Linux administrator needs to view the current runlevel of a system that uses systemd. Which command should be used?

Accepted Answer

systemctl get-default. On systemd systems, the concept of runlevels is replaced by targets. The systemctl get-default command shows the default target, which is the equivalent of the runlevel. Other options are either legacy or require interpretation.

Answer

runlevel

Answer

cat /etc/inittab

Answer

systemctl list-units --type=target

Question 11

A Linux administrator needs to ensure that a custom application starts automatically after the network is fully online and before any user logs in. The application runs as a systemd service. Which two actions should the administrator take? (Choose two.)

Accepted Answer

Run systemctl enable <service-name> to create the necessary symlinks. To ensure the service starts automatically after the network is fully online and before user logins, the unit file must be in /etc/systemd/system/ with WantedBy=multi-user.target, and then enabled with systemctl enable. This integrates the service into the boot process correctly.

Answer

Add After=network.target to the [Unit] section of the service

Answer

Set RemainAfterExit=yes in the [Service] section

Answer

Place the unit file in /etc/init.d/ and use update-rc.d to enable it

Question 12

A Linux administrator needs to ensure that a custom systemd service named myapp.service starts only after the network is fully online and the database service postgresql.service is running. Which directive should be used in the [Unit] section of myapp.service?

Accepted Answer

After=network-online.target postgresql.service. The After= directive in the [Unit] section defines ordering: the service will start only after the specified units have started. To ensure myapp.service starts after the network is online and postgresql.service is running, After=network-online.target postgresql.service is appropriate. However, for a complete solution, Requires= or Wants= should also be used to pull in those dependencies. The question specifically asks for the directive to ensure start order, so After= is the correct answer.

Answer

Requires=network-online.target postgresql.service

Answer

Before=network-online.target postgresql.service

Answer

Wants=network-online.target postgresql.service

Question 13

A Linux administrator needs to schedule a backup script to run every day at 2:30 AM. The script is located at /usr/local/bin/backup.sh. Which command should the administrator use to add this job to the crontab for the root user?

Accepted Answer

crontab -e. The correct method is to edit the root user's crontab with crontab -e and add a line specifying the schedule and the script path. This ensures the job runs daily at 2:30 AM under the root account. Other options either use the wrong format, assume an existing systemd unit, or schedule a one-time job.

Answer

at 2:30 AM /usr/local/bin/backup.sh

Answer

systemctl enable backup.timer

Answer

echo '30 2 * * * /usr/local/bin/backup.sh' >> /etc/crontab

Question 14

A Linux administrator is preparing a server for a new application and needs to configure an ext4 filesystem on a newly attached disk, /dev/sdc1, with a label of appdata so it can be referenced by label. The administrator also needs to ensure the filesystem is checked for errors on the next boot. Which TWO commands should the administrator run to accomplish these tasks? (Choose two.)

Accepted Answer

tune2fs -c 1 /dev/sdc1. Creating and labeling the new ext4 filesystem requires mkfs.ext4 with the -L option to set the appdata label. To ensure a check on the next boot, tune2fs -c 1 sets the maximum mount count to one, forcing an automatic fsck on the next mount. Listing tools and immediate check commands do not both format and schedule the check as required.

Answer

fsck -a /dev/sdc1

Answer

tune2fs -l appdata /dev/sdc1

Answer

e2fsck -f /dev/sdc1

Question 15

A Linux administrator is preparing a new server and needs to schedule a recurring backup job that runs every day at 2:30 AM. The job must run as the root user and should be defined in a location that is not user-specific. Which of the following should the administrator use?

Accepted Answer

Add an entry to /etc/crontab with the user field set to root.. The system-wide crontab file /etc/crontab includes an extra field for the username, allowing jobs to run as any user. By adding an entry with the user field set to root, the administrator ensures the backup runs daily at 2:30 AM as root, independent of any user's personal crontab. The /etc/cron.d/ directory also supports this but requires the user field; omitting it is invalid. The other options either tie the job to a user's crontab or lack time control.

Answer

Create a file in /etc/cron.d/ with the schedule and command, without a user field.

Answer

Add the job to /etc/cron.daily/ with a time specification.

Answer

Use the crontab -e command as the root user to add the entry.