LFCS Linux System Troubleshooting Quiz

1. What is the primary purpose of the /var/log/messages file in Linux troubleshooting?

Store kernel and system messages

Track user login attempts

Monitor network traffic

Log application errors only

2. True or False: The 'uptime' command shows system load average and how long the system has been running.

True

False

3. What does the 'iotop' command display?

Disk I/O usage by process

CPU usage by process

Memory usage by process

Network bandwidth by process

4. True or False: The 'lsof' command lists open files and can help identify which process is using a specific file.

True

False

5. To diagnose DNS resolution issues, which command would you use first?

Nslookup or dig

Ifconfig

Ping

Traceroute

6. True or False: The 'journalctl' command is used to query systemd journal logs.

True

False

7. Which systemd command checks if a service is currently running?

Systemctl status

Systemctl enable

Systemctl start

Systemctl list-units

8. What does the 'strace' command do in Linux troubleshooting?

Traces system calls and signals from a process

Traces network packets

Traces disk I/O operations

Traces memory allocation

9. Which file contains system configuration details that persist across reboots?

/etc/sysconfig

/proc/sys

/dev/

/tmp/

10. True or False: The dmesg command shows messages from the kernel ring buffer, useful for hardware troubleshooting.

True

False

11. Which command identifies which process is listening on a specific port?

Netstat -tulpn

Df -h

Top -u

Systemctl status

12. Which log file typically contains authentication and login failures?

/var/log/auth.log

/var/log/kernel.log

/var/log/boot.log

/var/log/cron.log

13. Which command helps identify which packages are installed and their versions?

Rpm -qa or dpkg -l

Ps aux

Lsmod

Uname -a

14. Which command displays real-time system resource usage including CPU, memory, and process information?

Top

Ps

Free

Iostat

15. To troubleshoot a hung process that won't respond, which signal would you send first?

SIGTERM (15)

SIGKILL (9)

SIGSTOP (19)

SIGHUP (1)

Submit

LFCS Linux System Troubleshooting Quiz

1. What is the primary purpose of the /var/log/messages file in Linux troubleshooting?

2.

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

2. True or False: The 'uptime' command shows system load average and how long the system has been running.

3. What does the 'iotop' command display?

4. True or False: The 'lsof' command lists open files and can help identify which process is using a specific file.

5. To diagnose DNS resolution issues, which command would you use first?

6. True or False: The 'journalctl' command is used to query systemd journal logs.

7. Which systemd command checks if a service is currently running?

8. What does the 'strace' command do in Linux troubleshooting?

9. Which file contains system configuration details that persist across reboots?

10. True or False: The dmesg command shows messages from the kernel ring buffer, useful for hardware troubleshooting.

11. Which command identifies which process is listening on a specific port?

12. Which log file typically contains authentication and login failures?

13. Which command helps identify which packages are installed and their versions?

14. Which command displays real-time system resource usage including CPU, memory, and process information?

15. To troubleshoot a hung process that won't respond, which signal would you send first?

16. To view a process's memory map and resource usage, you would use the ____ command.

17. The ____ command shows TCP/UDP statistics and active connections.

18. To check the current runlevel or target in a systemd system, use the ____ command.

19. To check disk space usage on all mounted filesystems, use the ____ command.

20. To check SELinux status and policy, you would use the ____ command.