Hi everyone,
I also found out i have this issue.
I did what @clabnet recommended:
#/bin/bash
#Remove images not used by containers
docker image prune -a
#Remove containers not used on last 24hours
docker container prune --filter "until=24h"
#Remove volumes not used by containers
docker volume prune
#Check space used by logs
journalctl --disk-usage
#Remove journald log files
journalctl --rotate
journalctl --vacuum-time=1m
and removed several Gb from my disk…but overlay is still 3.6Gb.
I noticed I have two overlay mounted disks, eacho of them 4.8Gb. Maybe this is related?