I did an update to a container and got a warning that my Docker image was 72%. I see this in the Memory area on the left on the main page too.

I Googled here and there and found a command that lists Image Space Usage:

docker system df -v

 

It shows some old containers I don't use any more that are not in the Docker list. It also shows multiple older images for Nextcloud. Probably from upgrading it. For example, here's a bunch of prior versions of Nextcloud that I think are in the image:

REPOSITORY                        TAG                IMAGE ID       CREATED         SIZE      SHARED SIZE   UNIQUE SIZE   CONTAINERS
linuxserver/nextcloud             27.1.0-ls271       844b0424c706   5 days ago      881.8MB   25.43MB       856.4MB       1
linuxserver/nextcloud             27.0.2-ls269       2c40df37dcb4   2 weeks ago     828.4MB   0B            828.4MB       0
linuxserver/nextcloud             27.0.2-ls267       88802f11c09b   4 weeks ago     828.4MB   25.43MB       803MB         0
linuxserver/nextcloud             27.0.2-ls266       4994a0316a3d   5 weeks ago     828.4MB   25.43MB       803MB         0
linuxserver/nextcloud             27.0.1-ls261       2832124f79ad   7 weeks ago     825.9MB   0B            825.9MB       0
linuxserver/nextcloud             27.0.1-ls260       0d0af4c9e41a   8 weeks ago     831.1MB   0B            831.1MB       0
linuxserver/nextcloud             27.0.0-ls255       4e1044e331d0   2 months ago    822.7MB   0B            822.7MB       0
linuxserver/nextcloud             27.0.0-ls252       09e7ddf65bd8   2 months ago    822.7MB   25.42MB       797.3MB       0

 

There's another one in there that is not in my current Docker tab list so I think it's just eating up space.

 

I don't want to do a prune because I think the prune would delete stopped containers, right?

 

Container size:

Total size                           13.1 GB                  1 GB                     66.3 MB

 

Docker volume info:

Total devices 1 FS bytes used 20.58GiB

devid 1 size 30.00GiB used 22.52GiB path /dev/loop2

 

What's the guidance here? Do I just go in and delete these old containers?

I took a risk and issued a "docker rmi <containerid>" on one of the containers that is not in my Docker list.

It deleted it along with a bunch of sha256 entries.

But the image shrank!

I'm onto something, but need to know if I just should do this with the other containers that are in there that seem to be taking up space.

Edited September 22, 20232 yr by nraygun

I think I want to use:

docker image prune -a

 

The dox say this:

To remove all images which are not used by existing containers, use the -a flag

 

So the stopped containers are using images so these images and containers shouldn't get deleted. But I think it should delete all the extra images that are taking up space that are not in use by a container.

 

Can someone confirm my understanding?

 

3 hours ago, nraygun said:

I took a risk and issued a "docker rmi <containerid>" on one of the containers that is not in my Docker list.

It deleted it along with a bunch of sha256 entries.

But the image shrank!

I'm onto something, but need to know if I just should do this with the other containers that are in there that seem to be taking up space.

Have you tried advanced view on docker page, It will show orphan images and you can delete from there.

 

Bingo! This is the way!

Thank you very much @SimonF!!!

My container is back down to 42% after deleting all of the old orphaned images that were in there. And none of the stopped containers were affected.

 

I guess I'll add this to the list of things to do when I update a container: Update it via a specific tag, check the .conf files, remove old images.