Sergey wrote a WIP 9pfs translator for the Hurd. 9P is a network protocol developed by Plan 9 that connects remote computers’ components. 9pfs is a 9P protocol client, which can read (there is some support for writing too) remote directories. 9P is perhaps not as robust or as fault tolerant as NFS, but it is a rather simple an ingenious protocol that works well enough for most use cases. The Hurd’s NFSv3 translator is an alternative to 9pfs.

Sergey currently uses 9pfs to build software on the Hurd that is edited on GNU/Linux. You just need to spin up a 9P server on GNU/Linux. diod is a good choice. But if the Hurd implemented virtio-9p, which qemu supports, then you would not need to run diod.

Please note that you can do the same thing with the Hurd’s nfsv3 client, even though the Hurd’s nfsv3 only supports UDP.

Once there exists a 9P server that runs on the Hurd the following would be possible.

• GNU/Linux could read/write several Hurd vms’ filesystems. For this to work, a developer needs to port or write a 9P server for the GNU/Hurd. Once that 9P server worked, then GNU/Linux could mount the Hurd’s filesystem. You just specify that the filesystem is 9p.

• The GNU/Hurd could read/write several subhurds’ filesystems and vice versa.