Portiner volumes

Whats that? Volumnes

Is safe delete unnused?

Unused means that there is no active container that is bound to the docker volume. So, deleting a container doesn’t necessarily remove the unnecessary docker volume unless you specifically delete the unused volumes at the time of container deletion. I usually mount persistent data off a NAS.

If there is some important data on these unused volumes, then a backup is recommended. Here are a couple of options:
https://docs.docker.com/desktop/backup-and-restore/

Hello @scascalesp

In my case I always delete unused volumes and such. For me there is no reason to keep them around So far I haven’t lost any data deleting unused volumes. As with anything you proceed at your own risk.