Debugging in Linux is essential for troubleshooting system issues, application bugs, or network problems. Here’s a simple guide to get you started with common Linux debugging tools and techniques.

1. Checking System Logs
Linux logs are a great starting point for debugging. Logs capture events related to the kernel, applications, and services.

View Logs with journalctl

# List all processesps aux# View processes in real-timetop

Find a Process by Name with pgrep

pgrep <process_name>

Debug a Process with strace
strace traces system calls made by a process.

strace -p <pid>`

Debug a Process with gdb
gdb is used for debugging compiled applications.

gdb <program_name> <pid>

1. Networking DebuggingCheck Active Connections with netstat or ss

Using netstat

netstat -tuln

Using ss

ss -tuln

Test Connectivity with ping or curl

ping <hostname_or_ip>

curl -v http://
Check Firewall Rules with iptables or ufw

Using iptables

sudo iptables -L -v

Using ufw

sudo ufw status verbose

1. Disk and Filesystem DebuggingCheck Disk Usage with df and du

Disk space usage

df -h

Directory size usage

du -sh <directory_name>

Check Disk Health with fsck and smartctl

Check and repair filesystem (run in unmounted mode)

sudo fsck /dev/sdX

Check disk health using smartctl

sudo smartctl -a /dev/sdX

1. Memory DebuggingCheck Memory Usage with free and vmstat

Memory usage

free -h

System performance and memory statistics

vmstat 1 5

Analyze Memory Leaks with valgrind

valgrind --leak-check=yes ./your_program

1. Kernel DebuggingCheck Kernel Messages with dmesg

dmesg | tail

Debug Kernel Panics with kdump
Ensure kdump is installed and configured for capturing kernel crash dumps.

sudo systemctl start kdump

Conclusion
Effective debugging in Linux requires a good understanding of system logs, processes, network, disk, and memory. Start with logs, monitor processes, trace system calls, and analyze system resources. Mastering these tools will help you quickly diagnose and resolve issues.