cannot write files bigger than free space on /

hi there, I set up the container with theese settings:

/dockerdata/download -> /share/downloads

system: 1proxmox > 2docker > (3portainer) > 4samba

/dir/ is an zfs dir mounted from proxmox to the docker os using proxmox

df -h root@docker:~# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/pve-vm--201--disk--0 99G 6.8G 88G 8% / zfspoolname 1.8T 74G 1.7T 5% /dockerdata < samba will access this none 492K 4.0K 488K 1% /dev udev 7.8G 0 7.8G 0% /dev/tty tmpfs 7.8G 0 7.8G 0% /dev/shm tmpfs 3.1G 560K 3.1G 1% /run tmpfs 5.0M 0 5.0M 0% /run/lock overlay 99G 6.8G 88G 8% /var/lib/docker/overlay2/foobar/merged overlay 99G 6.8G 88G 8% /var/lib/docker/overlay2/foobar/merged overlay 99G 6.8G 88G 8% /var/lib/docker/overlay2/foobar/merged overlay 99G 6.8G 88G 8% /var/lib/docker/overlay2/foobar/merged overlay 99G 6.8G 88G 8% /var/lib/docker/overlay2/foobar/merged overlay 99G 6.8G 88G 8% /var/lib/docker/overlay2/foobar/merged tmpfs 1.6G 0 1.6G 0% /run/user/0

Problem:

i can read using guest:guest
i can copy files that are bigger as the REMAINING space on docker root dir
i can ssh/scp into the 2docker host and place a 40GB file in dir datadir
i cannot copy bigger files file into Samba share, windows says "you need $filesize more space on the server to copy files"
no samba error in the docker logs

question:

how to make samba calculate the remaining space from the correct mountpoint?
how to change the samba config of the already deployed docker image without discarding the current settings?

2023-10-15T19:04:30.742986577Z usermod: no changes 2023-10-15T19:04:31.546571365Z smbd version 4.12.2 started. 2023-10-15T19:04:31.546590281Z Copyright Andrew Tridgell and the Samba Team 1992-2020 2023-10-15T19:04:31.601421049Z daemon_ready: daemon 'smbd' finished starting up and ready to serve connections

dperson / samba

cannot write files bigger than free space on / #448