diod

9p is such a great little protocol. diod[0] has a good amount of documentation on the protocol itself, but it's pretty simple. I have some notes here [1], but it's mostly just linking to primary sources. FUSE is great, but 9P is more general and has high quality implementations all over the place, even in Windows! One thing I'm not so sure about is the performance properties of 9p. I've seen some places indicate it's rather slow, but nothing definitive. Does anyone have any benchmarks or info on that? [0]: https://github.com/chaos/diod/blob/master/protocol.md [1]: https://athenaeum.wiki/Zettelkasten/9p

I don't know anything about that usage, but I've seen it mentioned in connexion with libvirt, and I assume there's a good reason it's maintained in NFS-Ganesha, though I haven't used it: https://github.com/nfs-ganesha/nfs-ganesha/wiki/9p 9p appears to be used on Tri-Labs HPC systems, which tend to be serious, if not entirely open: https://github.com/chaos/diod, https://github.com/chaos/9nbd; I'd seriously consider what they do if I had free reign building a new HPC system.

The 9P protocol truly is a beautiful work of engineering. There's actually another informal extension called 9P2000.e which is used by Erlang on Xen that adds session keys and a few new macro-operations (read whole file; overwrite contents) composed from lower level T/Rmsgs, but with ability to gracefully fall back to 9P2000. Linux v9fs has its own 9P2000.L in addition to the standard: https://github.com/chaos/diod/blob/master/protocol.md Either way, it's much more elegant and portable than something like FUSE.