Ben Chuanlong Du's Blog

It is never too late to learn.

Undelete Files in Linux

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

The best way to "recover deleted files" is really to avoid permanently delete files. It is suggested that you avoid using the rm command (unless you are 100% sure what you …

Tips on Linux

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Tricks and Traps

  1. Use full paths of commands when you use a batch account or schedule a cron job. The reason is that batch account and/or cron might have different …

PCIe BUS Error: Severity=Corrected, Type=Physical Layer

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Note: You might have to do this every time you upgrade your Linux kernel!!

Symptoms

Below are step-by-step symptoms from superficial to root causes.

  1. Your Linux system becomes very slow even …

Manage systemd Services and Units

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

  1. List all services names.

    service --status-all
    
  2. List all systemd units.

    systemctl
    
  3. Disable a service.

    systemctl disable service_name
    
  4. Check whether systemd is running as PID 1.

    ps --no-headers -o comm 1
    

A …

Tips on Shell Commands

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

explainshell.com

  1. command-not-found - Suggest installation of packages in interactive bash sessions

  2. nohup, disown

  3. nautilus-open-terminal

Configuration

https://github.com/thoughtbot/til/blob/master/bash/bash_profile_vs_bashrc.md#:~:text=bashrc%20is%20sourced%20on%20every …

Linux Administrator Tools

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

  1. BCC is a toolkit for creating efficient kernel tracing and manipulation programs leveraging extended Berkeley Packet Filters (eBPF).

  2. webmin, cloudmin, usermin

  3. id, adduser, gpasswd (recommended for adding/removing groups)

  4. uptime, top …