XK0-005 Practice Test 2 — 10 Questions

Question 1

A development team uses Git for version control and wants to automate the testing of every commit pushed to the repository. They have a Jenkins server running on a Linux machine. The team wants to automatically trigger a Jenkins pipeline job whenever a push is made to the main branch of their Git repository. The Jenkins server is behind a firewall and cannot be accessed from the internet. The Git repository is hosted on a private GitHub repository. Which of the following is the best approach to trigger the Jenkins job automatically?

Accepted Answer

Configure Jenkins to poll the Git repository every minute for changes.. Option B is correct because Jenkins' polling mechanism allows it to periodically check the Git repository for changes, which works even when the Jenkins server is behind a firewall and cannot receive inbound webhooks. Polling every minute provides near-real-time automation without requiring internet access to the Jenkins server, making it the only viable option given the network constraint.

Answer

Have developers manually click 'Build Now' in Jenkins after each push.

Answer

Configure a GitHub webhook to send a POST request to the Jenkins server.

Answer

Set up a cron job on the Git server to execute a script that triggers Jenkins.

Question 2

A Linux server with systemd is experiencing boot issues after a recent kernel update. Which command sequence should be used to boot into the previous kernel version?

Accepted Answer

Interrupt the boot process, select 'Advanced options' in GRUB, then choose the previous kernel.. Option B is correct because GRUB (Grand Unified Bootloader) stores multiple kernel versions in its menu. By interrupting the boot process and selecting 'Advanced options for Ubuntu' (or similar), you can choose the previous kernel entry, which loads the older kernel and its associated initramfs. This is the standard method to recover from a failed kernel update on systems using systemd and GRUB.

Answer

Boot from a live CD and run 'rpm -Uvh --oldkernel' to revert the kernel.

Answer

Use 'systemctl set-default multi-user.target' and reboot.

Answer

Use 'grub2-set-default' with the previous kernel entry before rebooting.

Question 3

A systems administrator wants to monitor system performance in real time. Which TWO commands can be used to display live updating information about processes, CPU, and memory usage? (Select TWO.)

Accepted Answer

top. The `top` command provides a real-time, dynamically updating view of system processes, CPU usage, and memory usage. It refreshes by default every few seconds, making it a standard tool for live performance monitoring. Similarly, `htop` is an enhanced interactive process viewer that offers a more user-friendly interface with color-coded, real-time updates on CPU, memory, and process information.

Answer

ps aux

Answer

sar -u 1 5

Answer

vmstat 1

Question 4

An administrator configures a new web server with Apache and needs to ensure it starts automatically after a system reboot. The administrator runs 'systemctl enable httpd' but the service still does not start after reboot. What is the most likely reason?

Accepted Answer

The httpd service is masked, preventing it from starting.. The most likely reason the httpd service does not start after reboot despite being enabled is that it is masked. A masked service is symlinked to /dev/null, which prevents systemd from starting it even if it is enabled. The 'systemctl enable' command creates the necessary symlinks for automatic startup, but a mask overrides this by blocking the service unit entirely.

Answer

The service name is incorrect; it should be 'apache2' instead of 'httpd'.

Answer

The administrator forgot to run 'systemctl start httpd' after enabling it.

Answer

The systemd daemon needs to be reloaded with 'systemctl daemon-reload'.

Question 5

A systems administrator needs to ensure that a custom service runs with a specific priority on a Linux server. Which command should the administrator use to achieve this?

Accepted Answer

nice -n -10 /usr/local/bin/myservice. Option C is correct because the `nice` command adjusts the CPU scheduling priority of a process at launch time. Using `nice -n -10` sets a higher priority (lower nice value) for the new service, ensuring it runs with the specified priority from the start. This directly meets the requirement to run a custom service with a specific priority.

Answer

renice -10 -p 1234

Answer

ionice -c 2 -n 0 -p 1234

Answer

chrt -r 99 /usr/local/bin/myservice

Question 6

Based on the exhibit, which statement is true about the sshd service?

Accepted Answer

The service is not enabled to start at boot.. The exhibit shows the output of `systemctl status sshd.service`. The line `Loaded: loaded (/usr/lib/systemd/system/sshd.service; disabled; vendor preset: enabled)` indicates the service is currently loaded but its enablement state is `disabled`, meaning it is not configured to start automatically at boot. The `Active: inactive (dead)` line confirms the service is not running now, but the question asks about boot-time behavior, which is governed by the `disabled` state. Therefore, option D is correct.

Answer

The service is masked.

Answer

The service is inactive.

Answer

The service has exited.

Question 7

A Linux administrator discovers that a user's home directory contains a file with setuid bit set, owned by root. The file is not part of any authorized software. What is the most appropriate immediate action?

Accepted Answer

Remove the setuid bit with 'chmod u-s <file>'. Option D is correct because the immediate priority is to neutralize the unauthorized setuid root binary, which poses a privilege escalation risk. Removing the setuid bit with 'chmod u-s' disables the ability for any user to execute the file with root privileges, containing the threat without destroying evidence that may be needed for forensic analysis. This aligns with security best practices of preserving artifacts while mitigating active risks.

Answer

Move the file to /tmp for further analysis

Answer

Delete the file immediately to remove the threat

Answer

Change the file owner to the user with 'chown user:user <file>'

Question 8

Which TWO of the following are valid methods to enforce disk quota limits on a Linux filesystem? (Select TWO.)

Accepted Answer

Using 'edquota' to set soft and hard limits for users. Option A is correct because 'edquota' is the standard interactive command used to set soft and hard disk quota limits for users or groups on a Linux filesystem. It opens the user's quota settings in a text editor, allowing precise configuration of block and inode limits. Option E is correct because 'quotaon' is the command that enables quota enforcement on a specified filesystem, activating the quota subsystem after limits have been defined.

Answer

Using 'setquota' to set limits in a script

Answer

Running 'repquota' to generate reports

Answer

Running 'quotacheck' to update quota files

Question 9

A user reports that they receive 'Permission denied' when trying to run a script located in their home directory. The script has permissions -rw-rw-r-- and is owned by the user. Which command should the user run to resolve the issue?

Accepted Answer

chmod u+x script.sh. The script has permissions -rw-rw-r--, meaning the owner (user) has read and write but not execute permission. To run it as a script, the execute bit must be set for the owner. The command chmod u+x script.sh adds execute permission for the user, allowing them to run the script directly.

Answer

chmod g-w script.sh

Answer

sudo chown user:user script.sh

Answer

chmod a+x script.sh

Question 10

A Linux administrator is troubleshooting network connectivity. The server can ping its own IP address but cannot ping the default gateway. The output of 'ip route show' is: 'default via 10.0.0.1 dev eth0 proto static metric 100'. The output of 'ping -c 1 10.0.0.1' fails with 'Destination Host Unreachable'. Which of the following is the MOST likely cause?

Accepted Answer

The subnet mask on eth0 is incorrect, causing the gateway to be considered on a different network.. The server can ping its own IP address, confirming that the local network stack and the eth0 interface are operational. However, the 'Destination Host Unreachable' error when pinging the default gateway (10.0.0.1) indicates that the host does not have a valid route to that destination. Since the default route exists, the most likely cause is an incorrect subnet mask on eth0, which causes the kernel to treat the gateway as being on a different network, thus failing to send ARP requests or forward packets to it.

Answer

The eth0 interface is down.

Answer

The gateway is down or not responding.

Answer

The default gateway is not set.