From SambaWiki

A clustered file server ideally has the following properties:

  • All clients can connect to any server.
  • A server can fail and clients are transparently reconnected to another server.
  • All servers can serve out the same set of files.
  • All file changes are immediately seen on all servers (distributed filesystem)
  • Ability to scale by adding more servers/disk backend.
  • Appears as a single large system.