XK0-006 System Management Practice Test 7 — 15 Questions

Question 1

A Linux administrator wants to search for all occurrences of the word 'ERROR' in log files under /var/log, ignoring case, and also print the line numbers. Which command should be used?

Accepted Answer

grep -rin 'ERROR' /var/log. The command 'grep -rin ERROR /var/log' combines -r (recursive search through directories), -i (case-insensitive match), and -n (print line numbers). This searches every file under /var/log for 'ERROR' regardless of case and prefixes each match with its line number, exactly matching the requirement.

Answer

grep -vi 'ERROR' /var/log

Answer

grep -rn 'ERROR' /var/log

Answer

find /var/log -name '*ERROR*'

Question 2

An administrator needs to replace all occurrences of 'oldhost' with 'newhost' in the configuration file /etc/hosts. Which command will perform the replacement and save the changes directly to the file?

Accepted Answer

sed -i 's/oldhost/newhost/g' /etc/hosts. The `-i` flag (in-place editing) tells `sed` to write the changes directly back to the file specified. Without `-i`, `sed` only prints the modified output to stdout and does not alter the original file. The substitution command `s/oldhost/newhost/g` performs a global replacement of all occurrences of 'oldhost' with 'newhost' on each line.

Answer

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

Answer

awk '{gsub(/oldhost/,"newhost")}1' /etc/hosts

Answer

grep -r 'oldhost' /etc/hosts | sed 's/oldhost/newhost/g'

Question 3

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 4

A service called 'myapp' fails to start automatically after a system reboot. The administrator wants to ensure the service starts at boot. Which systemctl command should be used?

Accepted Answer

systemctl enable myapp. The `systemctl enable myapp` command creates the necessary symlinks in the systemd unit configuration directories (typically `/etc/systemd/system/multi-user.target.wants/`) so that the `myapp` service is automatically started at boot. This is the correct approach because the question specifically asks to ensure the service starts after a reboot, not to start it immediately.

Answer

systemctl daemon-reload

Answer

systemctl start myapp

Answer

systemctl reenable myapp

Question 5

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 6

An administrator needs to view the last 20 lines of the systemd journal for the 'sshd' service. Which command should be used?

Accepted Answer

journalctl -u sshd -n 20. The command `journalctl -u sshd -n 20` directly queries the systemd journal for entries related to the sshd unit (`-u sshd`) and displays the last 20 lines (`-n 20`). This is the correct and efficient way to view recent journal entries for a specific service. It leverages journalctl's native filtering and tailing capabilities without piping or additional processing.

Answer

systemctl status sshd | tail -20

Answer

journalctl -u sshd --since '1 hour ago'

Answer

journalctl -u sshd -f

Question 7

A system administrator needs to install a package from a local RPM file without resolving dependencies automatically. Which command should be used?

Accepted Answer

rpm -i package.rpm. The `rpm -i package.rpm` command installs the specified RPM package without automatically resolving dependencies. The `-i` flag stands for 'install' and, unlike `-U` (upgrade) or higher-level tools like `yum` or `dnf`, it does not attempt to fetch or satisfy missing dependencies from configured repositories. This is the correct choice when the requirement is to install a local RPM file while explicitly avoiding automatic dependency resolution.

Answer

rpm -U package.rpm

Answer

yum localinstall package.rpm

Answer

dnf install ./package.rpm

Question 8

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.. Option C is correct because a hard link is simply a directory entry that points to the same inode, and inode numbers are only unique within a single filesystem, so the source and the new link must reside on the same filesystem (e.g., both under the same mount point). Option D is correct because hard links to directories are prohibited on Linux/Unix to prevent cycles in the directory tree, so the source must be a regular file (or another non-directory file type). Option E is correct because the link() system call requires an existing source pathname to resolve to an inode; you cannot create a hard link to a file that does not exist. Option A is not required since the SUID bit is a permission attribute unrelated to link creation, and Option B is wrong because a hard link may have any name and is not required to match the source filename.

Answer

The source file must have the SUID bit set.

Answer

The link must have the same name as the source.

Question 9

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 10

A technician notices a script fails to execute because the user does not have permission. The script currently has permissions 644. The technician needs to add execute permission for the owner only. Which command accomplishes this?

Accepted Answer

chmod u+x script.sh. The script currently has permissions 644, meaning the owner has read/write (6), group has read (4), and others have read (4). The requirement is to add execute permission for the owner only. The command `chmod u+x script.sh` adds (+) execute (x) permission to the user (u) — the owner — without affecting group or others. This is the precise and minimal command to achieve the goal.

Answer

chmod a+x script.sh

Answer

chmod 755 script.sh

Answer

chmod 744 script.sh

Question 11

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 12

Which command displays the disk usage of files and directories in a human-readable format (e.g., KB, MB)?

Accepted Answer

du -h. The `du -h` command (disk usage with human-readable flag) recursively summarizes disk usage for files and directories, appending size suffixes like K, M, G for kilobytes, megabytes, and gigabytes. This directly matches the question's requirement to display disk usage in a human-readable format.

Answer

df -h

Answer

ls -lh

Answer

stat -h

Question 13

A user reports that they cannot access a file because permission is denied. The file's permissions are -rwsr-xr-x. What special permission is set?

Accepted Answer

SUID. The permissions string `-rwsr-xr-x` shows an 's' in the owner's execute position, which is the SUID (Set User ID) bit. When SUID is set on an executable, the process runs with the effective UID of the file's owner rather than the invoking user — commonly used by utilities like `passwd` to allow normal users to modify protected files.

Answer

No special permission

Answer

Sticky bit

Answer

SGID

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 Linux engineer is troubleshooting a boot issue. The system boots to a command-line interface but does not start the graphical interface. Which systemd target should be set as default to boot into a graphical environment?

Accepted Answer

graphical.target. graphical.target is the systemd target that starts the graphical login manager and desktop environment (it pulls in multi-user.target plus the display manager). Setting it as the default with 'systemctl set-default graphical.target' causes the system to boot into the GUI. The current default can be verified with 'systemctl get-default'.

Answer

emergency.target

Answer

rescue.target

Answer

multi-user.target