relup(5)							       Files								  relup(5)

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 should be located in the OTP_ROOT/erts-EVsn/Vsn directory.

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

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

	 * Vsn = string() is the current version of the release.

	 * UpFromVsn = string() is an earlier version of the release to upgrade from.

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

	 * Instructions is a list of low-level release upgrade instructions, see appup(5) .

	   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() is an earlier version of the release to downgrade to.

       When  upgrading	from  UpFromVsn  with  release_handler:install_release/1,2  ,  there  does  not have to be an exact match of versions, but
       UpFromVsn can be a sub-string of the current release version.

SEE ALSO

       app(5), appup(5), rel(5), release_handler(3erl), systools(3erl)

Ericsson AB							   sasl 2.1.9.3 							  relup(5)