Analyze Disk space usage

My Hass.io installation is running out of space fast and I have a hard time analyzing what is using the data. How do I log into the Host OS?
If I log into HA via SSH and run df I get the following:

Filesystem           1K-blocks      Used Available Use% Mounted on
Filesystem                Size      Used Available Use% Mounted on
overlay                  30.8G     21.0G      8.2G  72% /
tmpfs                    64.0M         0     64.0M   0% /dev
tmpfs                     3.9G         0      3.9G   0% /sys/fs/cgroup
/dev/root                85.5M     85.5M         0 100% /dev/init
/dev/sda8                30.8G     21.0G      8.2G  72% /data 
/dev/sda8                30.8G     21.0G      8.2G  72% /config
/dev/sda8                30.8G     21.0G      8.2G  72% /ssl
/dev/sda8                30.8G     21.0G      8.2G  72% /addons
/dev/sda8                30.8G     21.0G      8.2G  72% /backup
/dev/sda8                30.8G     21.0G      8.2G  72% /share
/dev/sda8                30.8G     21.0G      8.2G  72% /etc/resolv.conf
/dev/sda8                30.8G     21.0G      8.2G  72% /etc/hostname
/dev/sda8                30.8G     21.0G      8.2G  72% /etc/hosts
shm                      64.0M         0     64.0M   0% /dev/shm
tmpfs                     3.9G         0      3.9G   0% /proc/acpi
tmpfs                    64.0M         0     64.0M   0% /proc/kcore
tmpfs                    64.0M         0     64.0M   0% /proc/keys
tmpfs                    64.0M         0     64.0M   0% /proc/timer_list
tmpfs                     3.9G         0      3.9G   0% /proc/scsi
tmpfs                     3.9G         0      3.9G   0% /sys/firmware

If I run space used on the root folder: du -h -s /

8.8G     /

So something outside of HA is using 12.3 GB

Ok, so I managed to get into the host.

mnt/data/docker/overlay2 contains 15.9 GB and probably around 50 “containers” of various sizes. I only have 14 Addons installed. Does that seem correct?

Hey, did you ever figure it out?

after updating last evening my disk that’s been 40% full for months, filled over night. I have no idea where to start…