Introduction

For any system administrator, Linux troubleshooting is an essential skill, and it's always better to have a few tricks up your sleeve when things go wrong. In this article, we'll take a look at some of the most useful Linux troubleshooting commands that every sysadmin should know.

1. dmesg

The dmesg command is a useful tool for troubleshooting kernel-related issues. It displays the kernel's ring buffer, which contains messages relating to the system's hardware and software status. To use the dmesg command, simply run:

    dmesg

This will show you the most recent kernel messages, which can be helpful in identifying issues related to hardware and software.

2. top

The top command is a valuable tool for monitoring system resources. It shows a real-time view of the system's CPU usage, memory usage, and process information. To start using the top command, execute:

    top

This command will display a list of running processes, along with information on CPU and memory usage. You can use top to identify any processes that are consuming excessive system resources and take appropriate action.

3. netstat

The netstat command is a useful tool for troubleshooting network-related issues. It displays information on current network connections, open ports, and other network-related statistics. To use the netstat command, run:

    netstat -tunap

This command will show you all the current TCP, UDP, and raw connections, as well as their state and associated processes. You can use netstat to identify any open ports or suspicious network connections.

4. ps

The ps command is a powerful tool for process management. It displays information on the system's running processes, including the process ID, CPU usage, memory usage, and more. To use the ps command, simply run:

    ps aux

This command will show you all the running processes, along with their corresponding information. You can use ps to identify any processes that are misbehaving and take appropriate action.

5. strace

The strace command is a powerful tool for troubleshooting system calls and signals. It allows you to monitor the behavior of a process, including the system calls that it makes and the signals that it receives. To use the strace command, simply run:

    strace -p [pid]

This command will attach strace to the process identified by the process ID (pid). You can use strace to identify any system calls or signals that are causing issues with a particular process.

Conclusion

These are just a few of the many Linux troubleshooting commands that every sysadmin should know. By mastering these commands, you'll be better equipped to handle any issues that arise on your system. Remember to always keep a cool head, stay calm, and troubleshoot effectively!