  Exported file systems with NFS


  NFS (Network File System) is the de facto standard _U_N_I_X to _U_N_I_X file
  sharing protocol. This means that _L_i_n_u_x can be a file server for any
  _U_N_I_X system out there.  This configuration screen allows you to "pub-
  lish" specific parts of your filesystem tree.

  11..  EExxppoorrttiinngg ffiilleessyysstteemmss


  Your _L_i_n_u_x system manages its files like they were part of a large
  tree.  You can specify which subdirectories (limbs) you are making
  available to which machines.

  Ultimately, you can specify that you export the root "/" with an empty
  list of machines. This means any machine will be able to access your
  files.

  By specifying one or more machines, you are restricting access.


  22..  OOppttiioonnss

  For each path you export, you can specify a list of hosts and a set of
  options associated with these hosts. If more than one host shares the
  same option set, you can enter them on the line, using the comma as
  the separator.

  Each option is presented with a checkbox. They are:


  +o  _M_a_y _w_r_i_t_e

     Writing to this directory is allowed for this client.

  +o  _R_o_o_t _p_r_i_v_i_l_e_g_e

     Without this option, all requests from user ID 0 (root) on the
     client are mapped to uid  NOBODY_UID  (a  compile-time option) on
     the server.

     Unless you have full trust in the client security, don't give away
     this option.

  +o  _T_r_a_n_s_l_a_t_e _s_y_m_b_o_l_i_c _l_i_n_k_s

     Convert absolute symbolic links (where the  link's contents starts
     with a slash) into relative links by prepending  the necessary
     number of ../'s to get from the directory containing the  link  to
     the root on the server.  (This has subtle, perhaps  questionable,
     semantics when the file hierarchy is not mounted at its root.)

  +o  _R_e_q_u_e_s_t _a_c_c_e_s_s _f_r_o_m _s_e_c_u_r_e _p_o_r_t

     Connections will be only accepted if they originate from a secure
     port on the client.


  33..  UUssiinngg wwiilldd ccaarrddss

  You may want to export a given path to all machines in a given domain.
  You are allowed to enter *.a_domain.com for example. Beware that the *
  does not match the dots. So if you want to give access to all machine
  of a_domain.com and all machines of all subdomains of a_domain.com,
  then you must enter:
               *.a_domain.com,*.*.a_domain.com


  44..  MMaacchhiinnee ttoo mmaacchhiinnee


  NFS introduces a fairly different approach to normal PC networking.
  Most PC file sharing protocols establish a relationship between one
  user and one or several servers. The machine used by the user is not
  relevant. Given that many PCs are running single-user operating
  systems, this scheme make sense.

  However, _U_N_I_X and _L_i_n_u_x are multi-user systems. NFS configuration is a
  machine to machine issue. One NFS server is granting access to
  different machines, either one by one, or to all machines on a given
  network. Once an NFS relationship is activated between one server
  machine and one client, all users on the client have access to the
  server, in the same way they have access to files and directories on
  the client machine.

  In fact, one user on the client machine will have about the same
  access as if he was logged into the server. His access will be limited
  to the different parts of the filesystem exported by the server.