How to free up space when using docker containers?

[FunkyBuddha]

I recently had a free space crisis. A docker application was consuming so much space that it started triggering alarms and notifications. The first thing I did was to stop container. Remove and delete the containers and images and found the disk space was not released. What the heck is going on?

Apparently, I forgot to issue this command:

• docker system prune (this will remove all stopped containers, unused images and  network address and free up the space for the OS).

 

Normally this command runs pretty quick, but in my case, it ran for over 12 hours due to the amount of space it has consumed. I was SSH'd into my server and was worried that if my connection disconnected, the command would abnormally terminate. Well, I did get disconnected, but the process continued to run in the background. After completing, it automatically rebooted the server and I got my free space back. I hope this helps the next person that encounters this problem.