XK0-006 Practice Test 13 — 15 Questions

Question 1

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 2

A cron job runs a script that fails because the command 'myapp' is not found. The script works when run manually by the same user. What is the most likely cause?

Accepted Answer

The PATH environment variable is different. When a cron job runs, it executes with a minimal environment, typically inheriting only a limited PATH (often just /usr/bin:/bin). The 'myapp' command is not found because its location (e.g., /usr/local/bin) is not in cron's PATH. When the same user runs the script manually, their interactive shell sources profile files (like .bash_profile or .bashrc) that set a more complete PATH, including the directory containing 'myapp'. This discrepancy is the most common cause of such failures.

Answer

The user does not have a home directory

Answer

The cron daemon is not running

Answer

The script has syntax errors

Question 3

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 4

What does the `set -x` command do when placed at the top of a bash script?

Accepted Answer

Displays each command before executing it. `set -x` enables a shell debugging mode that prints each command (after expansion) to stderr before executing it. This is commonly used in bash scripts to trace execution flow and debug complex logic.

Answer

Enables position parameters

Answer

Exits the script on error

Answer

Treats unset variables as errors

Question 5

A system administrator wants to ensure that a container can access host devices such as USB drives. Which Docker run option should be used?

Accepted Answer

--device /dev/ttyUSB0. The `--device` flag in Docker allows a container to directly access a specific host device, such as `/dev/ttyUSB0` for a USB drive or serial adapter. This grants the container read/write permissions to the device node without requiring full privileged access, making it the precise and secure option for this requirement.

Answer

--privileged

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--pid=host

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--net=host

Question 6

A system administrator is troubleshooting a service that fails to start with the error 'Unit failed to load: Invalid argument'. The service file is located in /etc/systemd/system. What is the most likely cause?

Accepted Answer

The service file has a syntax error. The error 'Unit failed to load: Invalid argument' in systemd indicates that the unit file parser encountered a directive or value it could not interpret. This is most commonly caused by a syntax error in the service file, such as a misspelled key, an invalid setting, or a malformed line. Systemd validates the file structure against its grammar; any deviation triggers this specific error.

Answer

The service binary is missing

Answer

The service requires a dependency that is not installed

Answer

The service is masked

Question 7

A Linux server is experiencing intermittent connectivity issues. The administrator reviews the system logs and finds the following messages: 'NETDEV WATCHDOG: eth0: transmit queue 0 timed out'. Which THREE actions are likely to resolve this issue? (Choose three.)

Accepted Answer

Disable NIC offloading features using 'ethtool -K eth0 tx off sg off'.. The 'NETDEV WATCHDOG: eth0: transmit queue 0 timed out' error often indicates that the NIC's hardware offloading features (such as TCP segmentation offload, scatter-gather) are causing the driver to hang or fail to complete transmissions. Disabling these offloads with 'ethtool -K eth0 tx off sg off' forces the CPU to handle packet segmentation and reduces the load on the NIC, which can resolve the timeout.

Answer

Increase the transmit queue length using 'ifconfig eth0 txqueuelen 10000'.

Answer

Change the MTU on the interface to 9000.

Question 8

A developer writes a Python script that uses the `requests` library to fetch data from an API. The script works on the developer's workstation but fails on the server with an import error. What is the most likely cause?

Accepted Answer

The `requests` module is not installed on the server. The `requests` library is a third-party Python package that must be installed separately via `pip` or a package manager. The script works on the developer's workstation because `requests` is present there, but fails on the server with an import error, indicating the module is missing from the server's Python environment. This is the most likely cause because an import error specifically points to a missing module, not to network or syntax issues.

Answer

The script uses an incorrect API endpoint

Answer

The server lacks internet connectivity

Answer

The script has a syntax error in the import statement

Question 9

A bash script uses a for loop to iterate over files in a directory. Which of the following correctly assigns each filename to the variable FILE?

Accepted Answer

for FILE in *.txt; do. The shell expands the wildcard pattern `*.txt` into a list of matching filenames before the `for` loop executes, and each filename is assigned to the variable `FILE` in turn. This approach is safe and efficient because it avoids parsing the output of `ls`, which can break with filenames containing spaces or special characters.

Answer

for FILE in $(ls *.txt); do

Answer

for FILE in 'ls *.txt'; do

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for FILE = *.txt; do

Question 10

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. top and htop are interactive process viewers that show real-time updates.

Answer

kill

Answer

jobs

Answer

ps aux

Question 11

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. find locates files based on criteria like -type f for regular files, -mtime for modification time, -size for size. The -exec option runs a command on each file found. gzip compresses files.

Answer

locate

Answer

xargs

Question 12

The system is a web server running Apache and MySQL. Based on the exhibit, which of the following is the most likely cause of the full disk?

Accepted Answer

Apache access and error logs are growing unchecked. Apache access and error logs are a common cause of full disks on web servers because they can grow unchecked, consuming all available space. By default, Apache logs are stored in /var/log/httpd/ or /var/log/apache2/ and are not rotated unless logrotate is configured. The exhibit likely shows a high percentage of disk usage in /var/log, confirming that log files are the culprit.

Answer

A user has filled their home directory

Answer

The /tmp directory is not being cleaned

Answer

The MySQL database has grown too large

Question 13

A system administrator is tasked with ensuring that users cannot delete files owned by other users in a shared directory. Which permission should be set on the directory?

Accepted Answer

Set the sticky bit. The sticky bit (chmod +t) on a directory restricts deletion so that only the file owner, the directory owner, or root can remove files, even if the directory has world-writable permissions. This directly prevents users from deleting files owned by others in a shared directory, which is the requirement.

Answer

Apply an ACL

Answer

Set the SGID bit

Answer

Set the SUID bit

Question 14

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. top shows real-time process information including CPU and memory usage. renice adjusts the priority of running processes.

Answer

kill

Answer

ps

Answer

nice

Question 15

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.. Setting the SGID bit (chmod g+s) on the directory ensures new files inherit the group ownership. Using an ACL with default entries (setfacl -d) can set default permissions 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.