Provided by: sfs-server_0.8-0+pre20050819.1-2_i386 bug


       sfs_hosts - Host to address mapping overriding DNS


       All SFS client software uses DNS to locate server names.  This is
       somewhat different from typical network utilities, which, often
       depending on a configuration file such as /etc/nsswitch.conf, can
       sometimes combine DNS with other techniques, such as scanning the file
       /etc/hosts or querying NIS (YP) servers.

       SFS relies exclusively on DNS for several reasons.  First, the file
       system is designed to provide a global namespace.  Using /etc/hosts,
       for example, it is common for a machine to have two names--for instance
       hostname, and  However, were the same file system
       to be available under two different self-certifying pathnames, several
       things would go wrong:  First, bookmarks to /sfs/@hostname,.../...
       would only work on the local network.  Even worse, it might be possible
       to lose a file by accidentally copying it onto itself, e.g., from
       /sfs/@hostname,.../... to /sfs/,.../....  Finally,
       SFS allows one to specify a TCP port number other than the default (4)
       using DNS SRV records, while non-DNS mechanisms have no means of
       specifying port numbers.

       Though DNS is fairly ubiquitous, there are situations in which one
       might like to have ‘‘internal’’ connections to SFS servers routed
       differently from ‘‘external’’ ones.  For example, when running SFS
       servers behind a NAT box, external connections would need to be
       directed to the external IP address of the NAT box, while it would be
       more efficient to route internal connections directly to the internal
       IP address, without going through the NAT.  In such situations, often
       the best solution is to set up a split DNS configuration.  When split
       DNS is not an option, however, the sfs_hosts mechanism will come in

       sfs_hosts is a superset of the standard /etc/hosts file format, that
       additionally allows one to specify a port number by appending it with a
       % character at the end of the address.  By default, the port number is
       4.  For example, the following two lines both specify that is running on port 4 of IP address

       If you really want /etc/hosts to override DNS with SFS, you can always
       run ln -s ../hosts /etc/sfs/sfs_hosts, but this is not recommended.
       Solutions involving DNS configuration will be much more scalable and


           Host to address mapping overriding DNS

       (Files in /etc/sfs supersede default versions in /usr/local/share/sfs.)


       dirsearch(1), newaid(1), rex(1), sfsagent(1), sfskey(1), ssu(1),
       sfs_config(5), sfs_srp_params(5), sfs_users(5), sfsauthd_config(5),
       sfscd_config(5), sfsrosd_config(5), sfsrwsd_config(5), sfssd_config(5),
       sfs_environ(7), funmount(8), nfsmounter(8), sfsauthd(8), sfscd(8),
       sfsrosd(8), sfsrwcd(8), sfsrwsd(8), sfssd(8), vidb(8)

       The full documentation for SFS is maintained as a Texinfo manual.  If
       the info and SFS programs are properly installed at your site, the
       command info SFS should give you access to the complete manual.

       For updates, documentation, and software distribution, please see the
       SFS website at