hosts.fs.local(4)

NAME
     hosts.fs.local - Local host information for Sun QFS shared
     file systems

SYNOPSIS
     /etc/opt/SUNWsamfs/hosts.fs.local

AVAILABILITY
     SUNWqfs

     SUNWsamfs

DESCRIPTION
     A /etc/opt/SUNWsamfs/hosts.fs.local file can reside on each
     host system included in the Sun QFS shared file system.
     This file is used in conjuntion with the shared hosts file,
     which resides in the shared file system and is initialized
     by sammkfs(1M) from hosts.fs(4), to initialize network
     connections between the hosts of a shared file system.  For
     more information, see the hosts.fs(4) and samsharefs(1M) man
     pages.

     The Sun QFS shared file system daemon uses the
     /etc/opt/SUNWsamfs/hosts.fs.local file and the shared hosts
     file present in the file system during initialization and
     reconfiguration to determine the server interfaces to which
     it should attempt to connect.  Its function is to restrict
     the server interfaces to which each client connects.  The fs
     portion of the name must be the family set name of the Sun
     QFS shared file system as specified in the mcf file.  For
     more information on the mcf file, see the mcf(4) man page.

     Each line in the hosts.fs.local file corresponds to a
     possible metadata server.  Each line contains the following
     fields:

     Field Number   Content

     1              The name of the host.  This field contains
                    the name of a potential metadata server host
                    to which the local host can connect.  This
                    field must match the first field of the host
                    in the shared hosts file.  You can use the
                    samsharefs(1M) command to verify the content
                    of the fields of the shared hosts file.

     2              A comma-separated list of host IP names or
                    addresses.  This should be a subset of the
                    second field from the same hosts entry in the
                    shared hosts file.

     The hosts.fs.local file is typically generated by copying
     the shared file system's shared hosts file to
     /etc/opt/SUNWsamfs/hosts.fs.local on each host.  Each line
     referring to a non-server host is then deleted, and the
     third through fifth fields in the remaining lines are
     deleted.  The network topology of the hosts is then examined
     in conjunction with the file, and the server interfaces that
     the local host should not attempt to connect to are removed
     from the second field.  When all of these have been removed,
     the file is written out.  The samd(1M) command is then used
     to cause any configuration changes to take effect.

     During startup and file system reconfiguration, the sam-
     sharefsd(1M) daemon attempts to connect to the server host.
     To do this, it searches the shared hosts file for the
     server's identity, and it extracts the list of IP names and
     addresses from the server's shared hosts file entry.  The
     daemon then looks up the server's name in the file system's
     local hosts file, if any.  If a local hosts file does not
     exist, the daemon uses the list from the shared hosts file.
     If the local hosts file does exist, then the corresponding
     list of host addresses is found in the local hosts file, the
     two lists of host addresses are searched (lexically) for
     common entries, and a common list is generated.  The
     ordering of the list is determined by the local hosts file
     (left-most first).  The names or addresses in the common
     list are looked up and used to attempt to connect to the
     server.  If an attempt fails, the daemon attempts using any
     remaining addresses in order until all the addresses have
     been tried.

EXAMPLES
     The following shared hosts configuration file supports a
     configuration in which two potential servers share a private
     interconnection and communicate to the other hosts sharing
     the file system using a separate network.  The examples in
     this section show the hosts.shsam1.local files that can be
     found on the various hosts.

     #
     # shsam1 config, titan/tethys servers, mimas/dione clients
     #
     # This file goes in titan:/etc/opt/SUNWsamfs/hosts.shsam1, and
     # is used by 'mkfs -S shsam1' to initialize the FS meta data.
     # Subsequent changes to the configuration are made using
     # samsharefs(1M).
     #
     titan   titan-ge,titan.xyzco.com 1 0 server
     tethys  tethys-ge,tethys.xyzco.com 2 0
     mimas   mimas.xyzco.com 0 0
     dione   dione.xyzco.com 0 0

     To ensure that titan and tethys always connect to each other
     through their private interfaces, titan-ge and tethys-ge,
     each requires a hosts.fs.local(4) file.  To achieve this,
     files titan:/etc/opt/SUNWsamfs/hosts.shsam1.local and
     tethys:/etc/opt/SUNWsamfs/hosts.shsam1.local would contain
     the following lines:

     #
     # shsam1 server local config, titan/tethys servers, mimas/dione clients
     #
     titan   titan-ge
     tethys  tethys-ge

     To avoid the delays and inefficiencies of having mimas and
     dione attempt to connect to titan and tethys through the
     inaccessible, private titan-ge and tethys-ge interfaces,
     mimas and dione should also have their own hosts.fs.local(4)
     files.  Files mimas:/etc/opt/SUNWsamfs/hosts.shsam1.local
     and dione:/etc/opt/SUNWsamfs/hosts.shsam1.local contain the
     following lines:

     #
     # shsam1 client local config, titan/tethys servers, mimas/dione clients
     #
     titan   titan.xyzco.com
     tethys  tethys.xyzco.com

FILES
     /opt/SUNWsamfs/examples/hosts.shsam1
                         Contains an example of a hosts.fs file.

     /opt/SUNWsamfs/examples/hosts.shsam1.local.server

     /opt/SUNWsamfs/examples/hosts.shsam1.local.client
                         Contain examples of hosts.fs.local
                         files.

SEE ALSO
     samfsck(1M), samfsconfig(1M), sammkfs(1M), samsharefs(1M),
     sam-sharefsd(1M).

     hosts.fs(4), mcf(4).