Before you start, be sure to read
Transitioning to Version 4.0.
That article outlines the reorganization of the Version 4.0 product
relative to Version 3.x.
A summary of the product migration process follows.
Most of this can be done for you by the product installation program.
Back up the current administrative configuration and user data files
in the current installation root directory.
See 3.2.2.2.1 for more information.
Stop and uninstall the current version of IBM WebSphere Application Server.
Drop the administrative database used for the previous installation
(for example, the WAS database)
Back up the database. You can use the database management system or simply rename
the database.
Restore the configuration in the new installation.
Note: If you have a Java Naming and Directory Interface (JNDI) client running on
WebSphere Application Server Version 3.5.x that needs to access a Version 4.0.x name
server, you need to ensure the following:
All 3.5 clients must be Version 3.5.3 or higher.
The WebSphere Application Server Version 3.5.3 and 3.5.4 installation on which the
3.5 client runs must have e-fix PQ51387 applied. Starting with 3.5.5, no e-fix is necessary.
Migrating administrative configurations
Tools for migrating administrative configurations are provided for
versions 3.02 and later.
This support enables either edition
of Version 3.x to be upgraded to either Advanced or Advanced Single Server edition
of Version 4.0.
There are two ways to migrate from Version 3.x:
Use the automated migration that is part of product installation.
Manually complete the same steps as the automated migration support would.
This might be necessary for nonstandard installations.