[SOLVED] Storing ISOs/VZdump on encrypted zfs dataset?

[Dunuin]

Hi,

As far as I see it is only possible to store VM images and containers inside a zfs dataset if it is added as "zfspool" storage.
It looks like it is possible to create a "dir" storage pointing its path to the mountpoint of a dataset to be able to store VZdump and ISOs on my zfs dataset.
But how to do that with encrypted datasets?
If I try to unlock my encrypted root dataset I only get this...

root@BM-Hypervisor:~# zfs mount -l -a
Enter passphrase for 'VMpool/VLT':
Enter passphrase for 'VMpoolHDD/VLT':
cannot mount '/VMpoolHDD/VLT': directory is not empty
cannot mount '/VMpoolHDD/VLT/DUMP': directory is not empty
cannot mount '/VMpoolHDD/VLT/ISO': directory is not empty

because the directories aren't empty anymore. It looks like ProxmoxVE mounts these folders at boot despite the datasets aren't mounted yet because I need to unlock them first which I do via ssh Minutes later.

How to do it right?

Edit:
Looks like this could be a solution: Link