Plan 9 File server
All permanent files are stored on the file server.
The file server responds to requests in a
protocol. The standard file server
stores files on WORM optical disks, with a conventional disk
as a cache, and a large memory to act as a cache for the disk.
The file server exists only to serve files. Some maintenance operations
are possible, but can only be conducted from the (physically secure)
file server console.