To configure the file server to listen for connections from remote hosts, first:
; 9fs 9fat
Then modify the bootargs in /n/9fat/plan9.ini:
For cwfs:
bootargs=local!/dev/sdXX/fscache -a tcp!*!564
For hjfs:
bootargs=local!/dev/sdXX/fs -m MMM -A -a tcp!*!564
Replace XX with the actual disk, and replace MMM with the size of the memory cache. You can use the same size that was automatically generated.