The dream of the plan9 filesystem may be alive in upspin (https://upspin.io/). Its a federated filesystem/protocol with a global namespace. The security story could arguably be described as a layer on top of any application built with it in mind.
I've just begun experimenting with it on my personal server and like it so far. Its still an early project though.
"Imagine you have something like a security camera, or you're a parent, you got a new newborn, you want a nursery camera.
You can put the camera into upspin by running a little directory storage server nearby -- or on the camera depending on how much control you have -- and then you've got access to the data whether it's a video stream or a series of static frames. Whatever it is. But it's encrypted, it's accessible only by the people in your family, which might be the name of an upspin group you created. It has you your wife and your other kids, or whatever. " - Rob Pike on Upspin at GopherCon 2017
Yes, definitely you can shard your filesystem however you like or mount any remote system locally if thats what your asking.
There is currently a little research into what it looks like to expose something like a webcam as a file and how streaming interfaces look in the system, but, the client to stream the webcam file is a little hacky still.
No, what I mean is that with 9p you can remote far more than just filesystems. It's an IP based layer with the Plan9 kernel being a router for 9p messages meaning you can do things like 'mount' an audio card from another machine into your 'namespace' and use it like it's local; no magic required. It's all in the kernel.
Since, this system is a layer outside the kernel, just a bunch of normal applications I don't think this would work as smoothly. I think you'd need a custom storage server to serve the audio card from the other machine. It doesn't by default serve the entire host filesystem.
That said, I think the goal of upspin is that you easily can re-use its interfaces to do things like this. There are already some guides about writing custom shim storage servers like that (the main example being a webcam server), but I think this sort of experimentation is still in the early phases.
I've just begun experimenting with it on my personal server and like it so far. Its still an early project though.