When I type:
$ mount|grep snap
/var/lib/snapd/snaps/ubuntu-core_352.snap on /snap/ubuntu-core/352 type squashfs (ro,relatime)
/var/lib/snapd/snaps/ubuntu-core_423.snap on /snap/ubuntu-core/423 type squashfs (ro,relatime)
/var/lib/snapd/snaps/ubuntu-core_122.snap on /snap/ubuntu-core/122 type squashfs (ro,relatime)
I see several old snap "mounted" and available while only the latest version is used as current in /snap/ubuntu-core
It's not a big deal but do I need older ubuntu core ? Isn't this a bug there are not deleted ? Could I simply unmount and delete the files ?