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 List of Services to Disable

Safe to Disable

1. bluetooth

   sudo systemctl disable bluetooth
   

2. openvpn

   sudo systemctl disable openvpn
   

3. virtualbox

   sudo systemctl disable virtualbox
   

4. packagekit

   sudo systemctl mask packagekit
   

   Notice that subcommand systemctl mask (instead of systemctl disable) is used as systemctl disable does not work in this case. For the difference between systemctl disable and systemctl mask, please refer to What is the difference between "systemctl mask" and "systemctl disable"? .

Controversial Ones

1. snapd

   sudo systemctl disable snapd.service
   sudo systemctl disable snapd.socket
   sudo systemctl disable snapd.seeded
   sudo systemctl disable snapd.snap-repair.timer
   

References

• How to know if I am using systemd on Linux?

• Convenient way to check if system is using systemd or sysvinit in BASH? [duplicate]

• How To Use Systemctl to Manage Systemd Services and Units

• What is the difference between "systemctl mask" and "systemctl disable"?