relup(4)                   Erlang Module Definition                   relup(4)

NAME
       relup - Release upgrade file

DESCRIPTION
       The release upgrade file describes how a release is upgraded in a
       running system.


       This file is automatically generated by systools:make_relup/3,4, using
       a release resource file (.rel), application resource files (.app), and
       application upgrade files (.appup) as input.


   File Syntax
       In a target system, the release upgrade file is to be located in
       directory $ROOT/releases/Vsn.


       The relup file contains one single Erlang term, which defines the
       instructions used to upgrade the release. The file has the following
       syntax:


              {Vsn,
                [{UpFromVsn, Descr, Instructions}, ...],
                [{DownToVsn, Descr, Instructions}, ...]}.


              Vsn = string()
         Current release version.



       UpFromVsn = string()
         Earlier version of the release to upgrade from.



       Descr = term()
         A user-defined parameter passed from the function
         systools:make_relup/3,4. It is used in the return value of
         release_handler:install_release/1,2.


       Instructions
         A list of low-level release upgrade instructions, see appup(4). It
         consists of the release upgrade instructions from the respective
         application upgrade files (high-level instructions are translated to
         low-level instructions), in the same order as in the start script.


       DownToVsn = string()
         Earlier version of the release to downgrade to.




   See Also
       app(4), appup(4), rel(4), release_handler, systools


Ericsson AB                        sasl 4.3                           relup(4)