Have the same issue. New install and /dev/root = 100%
root@ZimaOS:/root ➜ # df -h
Filesystem Size Used Avail Use% Mounted on
/dev/root 1.2G 1.2G 0 100% /
devtmpfs 24G 0 24G 0% /dev
/dev/nvme0n1p7 85M 219K 78M 1% /mnt/overlay
overlayfs 85M 219K 78M 1% /etc
tmpfs 24G 0 24G 0% /dev/shm
tmpfs 9.4G 5.0M 9.4G 1% /run
tmpfs 24G 1.9M 24G 1% /var
tmpfs 24G 0 24G 0% /tmp