XK0-006 System Management Practice Test 5 — 15 Questions

Question 1

A Linux server has a filesystem mounted at /data that is running out of space. The administrator wants to increase the size of the logical volume 'lv_data' by 10GB and then resize the filesystem online without unmounting it. The volume group 'vg_data' has 20GB of free space. Which sequence of commands will accomplish this?

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

Accepted Answer

lvextend -L +10G /dev/vg_data/lv_data && resize2fs /dev/vg_data/lv_data. To extend a logical volume and resize the filesystem online, the administrator should use lvextend followed by the appropriate filesystem resize tool. For ext4, resize2fs can grow the filesystem while mounted. The volume group has enough free space, so the commands will succeed without unmounting.

Answer

lvextend -L +10G /dev/vg_data/lv_data && e2fsck -f /dev/vg_data/lv_data

Answer

lvresize -L +10G /dev/vg_data/lv_data && resize2fs /dev/vg_data/lv_data

Answer

lvresize -L +10G /dev/vg_data/lv_data && xfs_growfs /data

Question 2

A Linux administrator needs to schedule a script /opt/backup.sh to run every day at 2:30 AM. The script must run as the user 'backup' and the schedule should survive system reboots. Which method should be used?

Accepted Answer

Add the line '30 2 * * * /opt/backup.sh' to the backup user's crontab. The backup user's crontab is the appropriate place to schedule a recurring task that runs as that user. Cron jobs in user crontabs persist across reboots and are executed with the user's permissions. This meets both the user and persistence requirements.

Answer

Add the line '30 2 * * * backup /opt/backup.sh' to /etc/crontab

Answer

Use the at command to schedule the script to run at 2:30 AM every day

Answer

Create a systemd timer unit that runs daily at 2:30 AM and enable it

Question 3

A Linux administrator needs to schedule a one-time job that runs a backup script at 2:00 AM on July 20. The job should not repeat. Which command should the administrator use?

Accepted Answer

at 2:00 AM July 20. The at command is specifically designed to schedule one-time jobs at a precise date and time. The syntax 'at 2:00 AM July 20' will queue the backup script to execute once at that moment. cron is for recurring tasks, batch runs when load is low, and systemd-run is more complex and not the standard tool for this simple one-time scheduling need.

Answer

crontab -e and add '0 2 20 7 * /path/backup.sh'

Answer

batch

Answer

systemd-run --on-calendar='2025-07-20 02:00' /path/backup.sh

Question 4

A Linux administrator needs to schedule a one-time job that will run at 2:30 AM on December 15. The job should execute a backup script located at /usr/local/bin/backup.sh. Which command will schedule this job correctly?

Accepted Answer

echo '/usr/local/bin/backup.sh' | at 02:30 AM Dec 15. The at command is designed for one-time scheduled jobs. Specifying '02:30 AM Dec 15' sets the exact date and time, and piping the script command schedules it. Cron would repeat annually, systemd-run adds complexity, and batch ignores the specified time. Thus at is the correct tool for a single future execution.

Answer

batch /usr/local/bin/backup.sh

Answer

systemd-run --on-calendar='2024-12-15 02:30' /usr/local/bin/backup.sh

Answer

crontab -e and add: 30 2 15 12 * /usr/local/bin/backup.sh

Question 5

A Linux administrator needs to configure a new hard disk (/dev/sdb) with a single partition that will be used as an ext4 filesystem. The partition must be aligned to 2048 sectors for optimal performance. Which TWO commands are necessary to create the partition and then make the filesystem? (Choose two.)

Accepted Answer

parted /dev/sdb mkpart primary ext4 2048s 100%. To create a partition and then a filesystem, you need a command to create the partition and a command to format it. The parted command with mkpart creates the partition with the specified alignment, and mkfs.ext4 formats the partition. These two commands accomplish the task.

Answer

mkfs -t ext4 /dev/sdb

Answer

fdisk /dev/sdb

Answer

parted /dev/sdb mklabel gpt

Question 6

A user reports that they cannot write to a file named 'report.txt' in their home directory, even though they own the file. The permissions are displayed as '-rw-r--r--'. Which command will allow the owner to write to the file?

Accepted Answer

chmod u+w report.txt. The file permissions '-r--r--r--' mean the owner has only read access. To allow writing, the owner's write permission must be granted. The chmod command with the u+w argument adds write permission for the user (owner), which is the correct solution to enable the owner to write to the file.

Answer

chmod o+w report.txt

Answer

chmod a-w report.txt

Answer

chmod g+w report.txt

Question 7

A Linux administrator is troubleshooting a system that fails to mount a new XFS filesystem at /data during boot. The administrator wants to verify the UUID of the filesystem and ensure the /etc/fstab entry is correct. Which TWO commands should the administrator use? (Choose two.)

Accepted Answer

lsblk -f. blkid and lsblk -f both display the UUID of block devices, which is essential for verifying or correcting the /etc/fstab entry. blkid is focused on a single device, while lsblk -f provides a broader view. The other commands either modify the UUID, attempt mounts, or check filesystem integrity, but none provide the UUID for comparison.

Answer

xfs_admin -u /dev/sdb1

Answer

fsck /dev/sdb1

Answer

mount -a

Question 8

A Linux administrator needs to schedule a backup script to run every day at 2:00 AM. The administrator also wants to ensure that the script runs only if the system is powered on at that time, and if missed, it should not run later. Which two commands or files should the administrator use to accomplish this? (Choose two.)

Accepted Answer

crontab -e. Both cron and systemd timers can schedule recurring tasks. The crontab -e command allows adding a cron job that runs daily at 2:00 AM and does not execute missed jobs. Similarly, a systemd timer with OnCalendar set to 02:00:00 and Persistent=false (the default) will run only if the system is up at that time. Anacron is designed to run missed jobs, which is the opposite of what is needed. The at command is for one-time tasks, and systemd-run transient timers are not persistent.

Answer

systemd-run --on-calendar='*-*-* 02:00:00' /path/to/backup.sh

Answer

at 2:00 AM

Answer

anacron

Question 9

A Linux administrator is configuring a systemd service that should start only after the network is fully online and the remote NFS mount at /mnt/nfs is available. The service unit file currently has After=network.target. Which additional directive should be added to ensure the service starts only when the NFS mount is mounted?

Accepted Answer

After=mnt-nfs.mount. In systemd, ordering dependencies are defined with After= and Before=. To ensure a service starts only after a mount is available, the service unit must have After=mnt-nfs.mount. This guarantees that the mount unit is active before the service starts, preventing failures due to missing NFS mount.

Answer

Wants=mnt-nfs.mount

Answer

Requires=mnt-nfs.mount

Answer

BindsTo=mnt-nfs.mount

Question 10

A Linux administrator needs to schedule a script to run every day at 3:30 AM. The script is located at /usr/local/bin/backup.sh and must run as the user 'backupuser'. Which crontab entry should be added to the backupuser's crontab?

Accepted Answer

30 3 * * * /usr/local/bin/backup.sh. The correct crontab entry uses the standard five time fields followed by the command. Placing it in backupuser's crontab ensures it runs as that user. The other options have invalid time fields, include an unnecessary username field, or use sudo unnecessarily.

Answer

30 3 * * * backupuser /usr/local/bin/backup.sh

Answer

3 30 * * * /usr/local/bin/backup.sh

Answer

30 3 * * * sudo -u backupuser /usr/local/bin/backup.sh

Question 11

A Linux administrator needs to configure a systemd service to start automatically at boot and also to restart automatically if it crashes. Which two directives should be added to the [Unit] and [Service] sections of the unit file, respectively? (Choose two.)

Accepted Answer

WantedBy=multi-user.target in the [Install] section. To start a service at boot, systemd uses the [Install] section with WantedBy=multi-user.target, which is activated by systemctl enable. To restart on crash, the [Service] section uses Restart=on-failure. Together, these directives ensure the service launches at boot and recovers from failures. The other options affect ordering, dependencies, or command execution but do not provide the required behaviors.

Answer

ExecStart=/usr/bin/myservice --daemon in the [Service] section

Answer

After=network.target in the [Unit] section

Answer

Requires=network.target in the [Unit] section

Question 12

A Linux administrator needs to identify all files in the /etc directory that are world-writable. Which TWO commands will accomplish this? (Choose two.)

Accepted Answer

find /etc -type f -perm /o+w. To find world-writable files, the find command with permission matching is appropriate. The -perm -o+w option matches files where the other write bit is set, and -perm /o+w matches files where any of the specified bits (other write) are set. Both correctly identify world-writable files in /etc. The other options either require additional write bits or search file contents instead of permissions.

Answer

ls -l /etc | grep 'w'

Answer

find /etc -type f -perm -222

Answer

grep -r 'w' /etc

Question 13

A Linux administrator is configuring a systemd service unit for a custom application. The application requires that the service be restarted automatically if it crashes, and that it starts only after the network is online. Which two directives should be added to the [Unit] and [Service] sections respectively? (Choose two.)

Accepted Answer

After=network-online.target. To automatically restart a service on crash, the Restart=on-failure directive in the [Service] section is appropriate. To ensure the service starts only after the network is online, the After=network-online.target directive in the [Unit] section is needed. The other options either do not enforce ordering (Wants), restart too broadly (Restart=always), or depend on an earlier network state (Requires=network.target).

Answer

Restart=always

Answer

Wants=network-online.target

Answer

Requires=network.target

Question 14

A Linux administrator is troubleshooting a system where a scheduled backup script is not running. The script is located at /usr/local/bin/backup.sh and is scheduled via a systemd timer. The administrator wants to verify that the timer is enabled and will trigger the associated service. Which TWO commands should the administrator use? (Choose two.)

Accepted Answer

systemctl list-timers --all. To verify that a systemd timer is enabled and will trigger, the administrator should check its enablement status and list all timers to see the next trigger. The commands systemctl is-enabled backup.timer and systemctl list-timers --all provide this information. The first confirms it starts at boot, and the second shows scheduled triggers.

Answer

systemctl status backup.timer

Answer

systemctl list-unit-files --type=timer

Answer

journalctl -u backup.service

Question 15

A Linux administrator is troubleshooting a system that fails to mount the /home filesystem at boot. The /etc/fstab entry for /home uses a UUID, but the administrator suspects the UUID is incorrect. Which command will display the UUIDs of all block devices to verify the correct UUID for the /home partition?

Accepted Answer

blkid. The blkid command is specifically designed to display block device attributes, including UUIDs. It provides a simple list that makes it easy to find the correct UUID for a partition. The other commands either do not show UUIDs or show them in a less direct manner.

Answer

fdisk -l

Answer

mount

Answer

lsblk -f