XK0-006 System Management Practice Test 13 — 15 Questions

Question 1

An administrator wants to gather information about disk usage for a specific directory and its subdirectories. Which TWO commands can be used for this purpose? (Choose two.)

Accepted Answer

du -sh /path. Du reports disk usage for the specified directory and, by default, recurses into its subdirectories, while -s summarizes the total into a single figure and -h presents it in human-readable units. Option D (du -h /path) is also correct because du -h /path likewise walks the directory tree and prints the disk usage of the directory and each subdirectory in human-readable form, satisfying the requirement to gather usage information for the directory and its subdirectories. Option B (df -h /path) is not correct because df reports filesystem-level free and used space for the mount point containing the path, not per-directory or per-subdirectory usage. Option C (ls -lh /path) is not correct because ls only lists file and directory entries with their sizes, without recursively totaling the disk usage of subdirectory contents. Option E (stat /path) is not correct because stat displays metadata such as inode, permissions, and timestamps for a single file or directory, not aggregated disk usage across a directory tree.

Answer

df -h /path

Answer

ls -lh /path

Answer

stat /path

Question 2

A Linux system has a directory with permissions drwxr-xr-x. A user in the group 'dev' tries to create a new file inside this directory. Which permission is missing that prevents the user from creating the file?

Accepted Answer

Write permission for the group. The directory has write permission for the owner, but only read and execute for the group. To create a file, the user needs write permission on the directory, which is not granted to the group.

Answer

Write permission for the owner

Answer

Sticky bit is set

Answer

Execute permission for the group

Question 3

An administrator wants to find all files larger than 100MB in the /var directory. Which command should be used?

Accepted Answer

find /var -type f -size +100M. The find command with -size +100M searches for files larger than 100 megabytes, and -type f restricts results to regular files. Running 'find /var -type f -size +100M' correctly locates all regular files under /var exceeding 100MB. This is the standard, precise way to search by size in Linux.

Answer

find /var -size +100kb

Answer

ls -l /var | grep 100M

Answer

du -sh /var/* | grep M

Question 4

A system administrator runs the command 'chmod 4755 /usr/local/bin/backup'. What effect does this have on the file?

Accepted Answer

Sets the SUID bit and gives rwxr-xr-x permissions. The 4 in the first digit sets the SUID bit, so the file runs with the owner's permissions. 755 sets rwxr-xr-x.

Answer

Sets the sticky bit and gives rwxr-xr-x permissions

Answer

Sets the SGID bit and gives rwxr-xr-x permissions

Answer

Sets the SUID bit and gives rwxrwxr-x permissions

Question 5

Which command displays the current default umask value for a user?

Accepted Answer

umask. The umask command, when run without arguments, prints the current file-mode creation mask for the shell session. This mask determines which permission bits are removed from newly created files and directories.

Answer

chmod

Answer

set

Answer

ls -l

Question 6

A system administrator needs to monitor real-time process information and system resource usage. Which two commands can be used for this purpose? (Choose two.)

Accepted Answer

top. Option B (top) is correct because it launches an interactive, real-time process viewer that continuously refreshes CPU, memory, load average, and per-process statistics, exactly matching the requirement for live process and resource monitoring. Option C (htop) is also correct because it is an enhanced interactive process viewer that provides the same real-time monitoring with additional features such as colorized output, scrollable process lists, and per-core CPU meters. Option A (kill) is incorrect because it only sends signals to terminate or control existing processes and does not display monitoring data. Option D (jobs) is incorrect because it merely lists jobs in the current shell session and shows no system resource usage. Option E (ps aux) is incorrect because it produces a static snapshot of processes at the moment of execution rather than continuous real-time monitoring.

Answer

kill

Answer

jobs

Answer

ps aux

Question 7

A user wants to view the contents of a text file one page at a time. Which two commands can be used? (Choose two.)

Accepted Answer

less. Both less (A) and more (E) are paging utilities that display a text file one screenful at a time and pause for the user to scroll, which directly matches the requirement. less is the more capable pager, supporting both forward and backward navigation plus searching, while more provides basic forward paging and is available on virtually all Unix-like systems. The other commands do not page output: cat (B) dumps the entire file to standard output at once, and tail (C) and head (D) only print the last or first lines (10 by default) respectively, so none of them let the user view the file page by page.

Answer

cat

Answer

tail

Answer

head

Question 8

A system administrator is investigating a performance issue and wants to view kernel-related messages. Which three commands can be used to access kernel ring buffer messages? (Choose three.)

Accepted Answer

dmesg. Option B (dmesg) is correct because dmesg directly reads and prints the kernel ring buffer, which is exactly the kernel-related message store the administrator needs. Option C (cat /var/log/kern.log) is correct because on many Linux distributions the kernel ring buffer messages are persisted to /var/log/kern.log, so reading that file exposes kernel messages. Option D (journalctl -k) is correct because the -k (or --dmesg) flag restricts systemd journal output to kernel messages only, providing access to kernel ring buffer content. Option A (tail -f /var/log/syslog) is not correct here because syslog is a general system log that may include kernel messages only indirectly and is not the kernel ring buffer itself. Option E (systemctl status) is not correct because it reports the status of systemd units and does not display kernel ring buffer messages.

Answer

tail -f /var/log/syslog

Answer

systemctl status

Question 9

An administrator needs to create a hard link to an existing file. Which two statements are true about hard links? (Choose two.)

Accepted Answer

Hard links are indistinguishable from the original file. Option C is correct because a hard link is simply another directory entry that points to the same inode, so it has identical permissions, ownership, timestamps, and content as the original file and cannot be distinguished from it by normal file operations. Option D is correct because creating a hard link with ln (without -s) increments the inode's link count and gives the new name the same inode number as the original file, which is why both names reference the same data blocks. Option A is wrong because hard links to directories are prohibited on Linux filesystems to prevent cycles in the directory tree. Option B is wrong because a hard link must reside on the same filesystem as the target file, since inode numbers are only unique within a single filesystem. Option E is wrong because deleting the original name only decrements the link count; the data remains accessible through the remaining hard link until the link count reaches zero.

Answer

Hard links can be created for directories

Answer

Hard links can be created across different filesystems

Answer

Deleting the original file removes the hard link

Question 10

A technician wants to extract the third column of a tab-separated file and sort the output uniquely. Which three commands can be combined using pipes to achieve this? (Choose three.)

Accepted Answer

cut -f3. Option A, `cut -f3`, is correct because `cut` with the `-f3` flag extracts the third field from each line, and with tab as the default delimiter it directly targets the third column of a tab-separated file. Option D, `sort`, is correct because it orders the extracted lines so that duplicate values become adjacent, which is a prerequisite for `uniq` to collapse them. Option E, `uniq`, is correct because it removes adjacent duplicate lines, producing the unique output the technician wants when chained after `sort`. Option B, `tee`, is not appropriate because it merely splits output to a file and standard output rather than extracting or deduplicating data. Option C, `wc -l`, is not appropriate because it only counts lines and does not extract or sort columns.

Answer

tee

Answer

wc -l

Question 11

A Linux administrator needs to create a new user account 'analyst' with a home directory at /home/analyst and the default shell set to /bin/bash. The user should also be added to the existing supplementary group 'research'. Which command will accomplish this in a single step?

Accepted Answer

useradd -m -s /bin/bash -G research analyst. The useradd command with -m creates the home directory, -s specifies the shell, and -G adds the user to supplementary groups. This single command meets all specified conditions without extra steps, making it the correct solution.

Answer

groupadd research && useradd -m -s /bin/bash -g research analyst

Answer

usermod -m -s /bin/bash -G research analyst

Answer

adduser analyst -m -s /bin/bash -g research

Question 12

A Linux administrator is troubleshooting a systemd service that fails to start. The service unit file is located at /etc/systemd/system/myservice.service. After editing the unit file, the administrator runs systemctl start myservice, but the service still uses the old configuration. Which command should be run to ensure systemd reloads the modified unit file?

Accepted Answer

systemctl daemon-reload. After modifying a systemd unit file, the systemd manager must reload its configuration to recognize the changes. The systemctl daemon-reload command performs this reload, ensuring subsequent start or restart operations use the updated unit file.

Answer

systemctl restart myservice

Answer

systemctl reenable myservice

Answer

systemctl reload myservice

Question 13

A Linux administrator needs to scan all currently connected USB devices and display detailed information such as vendor ID, product ID, and device class. Which command should the administrator run?

Accepted Answer

lsusb. The lsusb command queries the USB subsystem and prints a line for each connected USB device, including vendor and product IDs, device class, and bus topology. It is the standard utility for quickly enumerating USB devices on a Linux system without needing elevated privileges.

Answer

lshw -class usb

Answer

lspci

Answer

lsblk

Question 14

A Linux server has a logical volume that is running out of space. The administrator extends the underlying volume group by adding a new physical volume, then extends the logical volume and resizes the filesystem. Which command should be used to resize the ext4 filesystem after extending the logical volume?

Accepted Answer

resize2fs /dev/vg0/lv_data. After extending the logical volume, the ext4 filesystem must be resized to use the new space. The resize2fs command is designed for this purpose and can resize ext4 filesystems online. It is the correct tool after lvextend.

Answer

xfs_growfs /dev/vg0/lv_data

Answer

lvextend -r /dev/vg0/lv_data

Answer

vgextend vg0 /dev/sdb1

Question 15

A junior administrator needs to add a persistent mount entry for a new XFS filesystem on /dev/sdb1 at the /data directory so it is mounted automatically at every boot. The administrator opens /etc/fstab and must identify the correct field order for the entry. Which field order should be used in the /etc/fstab line?

Accepted Answer

device, mount point, filesystem type, mount options, dump, fsck pass. The /etc/fstab format is strictly positional: source device, mount point, filesystem type, options, dump flag, and fsck pass. For an XFS volume on /dev/sdb1 mounted at /data, the entry must follow that order so systemd and mount can resolve the device and target correctly and apply options such as defaults or noatime. Misordering any field prevents the persistent mount from working at boot.

Answer

mount point, device, filesystem type, dump, mount options, fsck pass

Answer

UUID, filesystem type, mount options, mount point, dump, fsck pass

Answer

device, filesystem type, mount point, fsck pass, dump, mount options