Ok. I’ve not tried such granular permissions on the NAS but from what I’ve seen it is possible. The permissions are stored in /etc/trustees.conf. For the Public folder the entry is, for my My Book Live Duo is …
I changes this to …
… so only my user account and the admin account has access.
Note. /dev/md3 is specific for MyBook Live Duo. It’ll be different for the single drive MyBook Live.
With the MBL and MBLD it’s a bit more complicated becayse when the Dashboard UI does it’s thing it creates a file /tmp/trustees.mod. In here is the contents of the trustees.conf file as well as entries to deny the other user accounts access to the folders used for SMB shares. The same changes need to be done to this file as you do to trustees.conf and also you will need to apply the necessary DENY entries in trustees.mod
Once you’ve done all that you activate the revised trustees configuration using …
settrustees -f /tmp/trustees.mod
All I wanted to do is eliminate the Public share without actually removing it because thare are a fair few other things on the NAS that I guess reply on the /shares/Public folder to exist, so I just changed the permissions which works brilliantly for me and as long as I don’t make any changes to the Public share on the Dashboard UI then my tweak persists even through a firmware upgrade.
I see no reason why you can’t apply specific permissions to a sub-directory under a share but be aware that it may break a script or few. From what I’ve witnessed I think it won’t.
As long as you make sure you can reverse all the changes back to the original settings, before you start twiddling, then I guess you should be ok.
Obviously if you screw anything up then it’s your NAS. I’ll have a fiddle too and see if any permissions set beyond what the Dashboard UI sets will stay put.
On first thoughts I suspect what you want should be an easy thing to do and the Dashboard UI should leave your custom trustee settings alone with the settings persisting across firmware updates.
It’s not just FTP that is affected. It’s all the daemons. NetATalk, Samba, FTP, etc… Not sure about the iTunes daemon, the DNLA daemon and the remote access Daemon.