Basically a symlink pointing to a folder mounted via nfs. The recordings are done directly on the nas, but available space is reported by the stick (couldn't use an old 16MB sd card as a recording device

It works very well even if the hdd of my NAS is in standby and takes ~10s to spin up.
The only problem I have is if I reboot the NAS the mount will be unavailable or if there is a power outage and the nas takes a long time to start.