Container access to host filesystem

I’m on 25.10 CE, and I’m trying to semi-automate pruning the massive number of redundant files on my NAS. A number of promising packages exist for this job. Since installing software directly on the NAS is practically verboten (and probably not a good idea) the obvious approach is to create a container and add the root dataset of the whole NAS store as a “disk.” That works… almost? From the container I can see the items directly in the mapped directory, but all of its subdirectories appear to be empty. In my research I discovered a mention of giving the user truenas_container_unpriv_root access on the host side. The UI for setting dataset permissions seems to know about this user, but giving it full access (recursively) has no apparent effect, and the shell doesn’t know about the user—it’s not listed in /etc/passwd nor can I su truenas_container_unpriv_root.

Does anyone know the piece I’m missing here? Many thanks in advance!

…and just like that I think I’ve solved it. Directory mapping only goes as far as the dataset boundary. Any child datasets (which were the only subdirectories) appear empty unless you map them too. truenas_container_unpriv_root seems to be irrelevant. Now to wait while nfs4xdr_winacl finishes undoing the ACL changes I made!