Linux+ V8 Cloud Troubleshooting Quiz

1. To diagnose certificate issues on a cloud host running a web service, which command validates an SSL certificate?

Openssl x509 -in cert.pem -text -noout

Cat /etc/ssl/certs/ca-certificates.crt

Ls -la /etc/ssl/private/

Grep -r ssl /etc/

2. To verify that SELinux is not blocking cloud service operations, which command checks the SELinux status?

Getenforce or sestatus

Semanage login -l

Getsebool -a

Semodule -l

3. When a cloud Linux host loses connectivity to a cloud metadata service, which network interface should you check first?

The default gateway and routing table

The loopback interface

The MAC address table

The ARP cache only

4. A cloud host's filesystem is nearly full. Which command identifies the largest directories consuming disk space?

Du -sh /* | sort -hr

Df -h

Ls -lah

Find / -type f -size +100M

5. To troubleshoot a failed systemd service on a cloud host, which command shows why the service did not start?

Systemctl status -l service_name

Systemctl list-units --all

Systemctl show service_name

Systemctl daemon-reload

6. A cloud host exhibits high load average but low CPU usage. What is the most likely cause?

High disk I/O wait or network latency

Insufficient RAM

Firewall blocking traffic

Incorrect kernel parameters

7. When a cloud service fails to bind to a required port, which command identifies which process holds the port?

Lsof -i :port_number

Netstat -an

Ss -tulpn

Ps aux | grep port_number

8. A cloud-connected Linux host cannot resolve a specific domain name. Which tool tests DNS resolution directly?

Nslookup or dig

Ping hostname

Traceroute hostname

Telnet hostname 53

9. To check if a cloud host has correct time synchronization, which command displays NTP status?

Timedatectl or ntpq -p

Date

Uptime

Systemctl status ntp

10. A firewall rule blocks traffic to a cloud host. Which utility shows active firewall rules on a Linux system?

Iptables -L or ufw status

Route -n

Ip addr show

Arp -a

11. When a cloud-connected Linux host loses network connectivity, which command best displays the current status of all network interfaces?

Ip link show

Netstat -an

Arp -a

Route -n

12. A cloud host reports 'out of memory' errors. Which command shows the top memory-consuming processes?

Top -o %MEM

Free -h

Ps aux

Vmstat 1 5

13. When troubleshooting container connectivity issues, which command shows all active network connections for a container?

Docker inspect container_id

Docker logs container_id

Docker stats container_id

Docker events

14. A user reports slow authentication on a cloud-connected Linux host. Which service typically handles user authentication?

Sssd or pam

Httpd

Named

Rsync

15. To verify that a specific port is open and listening on a cloud host, which command is most reliable?

Netstat -tulpn | grep :port_number

Ping -p port_number hostname

Arp -a

Traceroute hostname

16. A cloud host shows high disk I/O utilization. Which tool provides real-time disk performance metrics?

Iostat

Vmstat

Top

Ps

17. When SSH fails on a cloud Linux host, which port is the default SSH service listening on?

22

2222

3389

5900

18. A service fails to start after a cloud host reboot. Which command shows the detailed error message from systemd?

Journalctl -u service_name -n 50

Systemctl status service_name

Tail -f /var/log/syslog

Dmesg | grep service_name

19. To diagnose CPU throttling on a cloud instance, which file in /proc would you examine?

/proc/cpuinfo

/proc/meminfo

/proc/uptime

/proc/loadavg

20. A container on a cloud host cannot reach external DNS servers. Which file should you check first to verify DNS configuration?

/etc/resolv.conf

/etc/network/interfaces

/etc/hostname

/etc/hosts

Linux+ V8 Troubleshooting Cloud Connected Linux Hosts Quiz

1. To diagnose certificate issues on a cloud host running a web service, which command validates an SSL certificate?

2.

What first name or nickname would you like us to use?

2. To verify that SELinux is not blocking cloud service operations, which command checks the SELinux status?

3. When a cloud Linux host loses connectivity to a cloud metadata service, which network interface should you check first?

4. A cloud host's filesystem is nearly full. Which command identifies the largest directories consuming disk space?

5. To troubleshoot a failed systemd service on a cloud host, which command shows why the service did not start?

6. A cloud host exhibits high load average but low CPU usage. What is the most likely cause?

7. When a cloud service fails to bind to a required port, which command identifies which process holds the port?

8. A cloud-connected Linux host cannot resolve a specific domain name. Which tool tests DNS resolution directly?

9. To check if a cloud host has correct time synchronization, which command displays NTP status?

10. A firewall rule blocks traffic to a cloud host. Which utility shows active firewall rules on a Linux system?

11. When a cloud-connected Linux host loses network connectivity, which command best displays the current status of all network interfaces?

12. A cloud host reports 'out of memory' errors. Which command shows the top memory-consuming processes?

13. When troubleshooting container connectivity issues, which command shows all active network connections for a container?

14. A user reports slow authentication on a cloud-connected Linux host. Which service typically handles user authentication?

15. To verify that a specific port is open and listening on a cloud host, which command is most reliable?

16. A cloud host shows high disk I/O utilization. Which tool provides real-time disk performance metrics?

17. When SSH fails on a cloud Linux host, which port is the default SSH service listening on?

18. A service fails to start after a cloud host reboot. Which command shows the detailed error message from systemd?

19. To diagnose CPU throttling on a cloud instance, which file in /proc would you examine?

20. A container on a cloud host cannot reach external DNS servers. Which file should you check first to verify DNS configuration?