From what I can see, it isn’t possible to set a data limit on a share. It appears to be a much requested option.
For myself, I want to set a very modest limit (64GB) on one of my shares in order to force my security camera to start overwriting the existing files.
The data is being accessed by my camera via NFS and from the tests I’ve done, that amount of data will represent about 1 months recordings. I would prefer to automate the process rather than having to go in and manually delete stuff. It seems like a very basic requirement to me.