Linux+ Troubleshooting Quiz: Can You Fix The System?

1. A cron job fails silently. Where are cron errors logged?

/var/log/cron

/var/log/syslog or journalctl

/etc/cron.d/

~/.cron_log

2. A service port is already in use by another process. Which command identifies the conflicting process?

Netstat -tlnp

Ss -tlnp

Lsof -i :PORT

All of the above

3. Kernel parameters need adjustment. Which file is persistent across reboots?

/proc/sys/

/etc/sysctl.conf

/sys/kernel/

/etc/syscall.d/

4. A daemon fails to start at boot. Which command enables it permanently?

Systemctl start servicename

Systemctl enable servicename

Chkconfig servicename on

Service servicename start

5. The system is unresponsive. Which tool shows CPU load and memory in real-time?

Top

Htop

Ps aux

Both a and b

6. A library dependency is missing. Which command finds which package provides it?

Apt search

Apt-file search

Ldconfig -p

Ldd

7. The network interface is down. Which command brings it up?

Ifup eth0

Ip link set eth0 up

Systemctl restart networking

All of the above

8. A user cannot access a file owned by root. Which permission mode allows group read/write?

Chmod 640

Chmod 644

Chmod 660

Chmod 666

9. The filesystem shows corruption. Which tool safely checks and repairs it?

Fsck (unmounted)

Mount -o remount,rw /

E2fsck

Badblocks

10. SELinux blocks a legitimate service. Which command shows the denial?

Getenforce

Ausearch -m avc

Semanage

Getsebool

11. A system boots to GRUB but fails to load the kernel. Which file should you check first?

/boot/grub/grub.cfg

/etc/fstab

/proc/cmdline

/var/log/boot.log

12. Memory usage is high but no processes show significant RAM usage. What is likely consuming it?

Buffer cache

Kernel memory leak

Swap usage

Memory mapped files

13. A process is stuck in an uninterruptible state (D). What is the only way to remove it?

Kill -9

Reboot the system

Kill -SIGKILL

Wait for the I/O operation to complete

14. The system cannot resolve DNS names. Which file should you verify first?

/etc/hosts

/etc/resolv.conf

/etc/hostname

/etc/network/interfaces

15. A disk is 95% full. What is the first step in troubleshooting?

Delete old log files

Use 'du' to find large directories

Resize the partition

Add a new disk

16. Which command identifies open file handles and which process holds them?

Lsof

Fuser

Ps aux

Strace

17. A service crashes repeatedly. Where are systemd service logs stored by default?

/var/log/messages

/var/log/syslog

Journalctl (in systemd journal)

/var/log/service.log

18. The system has no internet connectivity. Which command tests the default gateway?

Ping 8.8.8.8

Ping $(ip route | grep default | awk '{print $3}')

Traceroute 8.8.8.8

Netstat -r

19. A user reports slow file access. Which tool shows real-time disk I/O performance?

Iostat

Vmstat

Iotop