Roadmap: Migrating and coexisting application servers
Migrating involves collecting the configuration information from a previous release of a WebSphere® Application Server and merging it into a configuration for a new release. Coexisting involves running a new release of a WebSphere Application Server and an earlier release simultaneously on the same machine.
Before you begin

This article is about profile configuration migration. To migrate your applications to the latest version, use the WebSphere Application Server Migration Toolkit. For more information, see the Migration Toolkit on WASdev.
sptcfgRead Overview of migration, coexistence, and interoperability and Migration considerations. For resources to help you plan and perform your migration, visit Knowledge Collection: Migration planning for WebSphere Application Server.
The migration tools basically save the existing WebSphere configurations and user applications in a backup directory and then process the contents of this backup directory to migrate the configurations and your applications from previous WebSphere Application Server releases to the latest release.
If you have a previous version of WebSphere Application Server, you must decide whether to migrate the configuration and applications of the previous version to the new version.
If you run two different versions of the application server at the same time, the two versions are coexisting. For example, if Version 7.0 and 8.5 application servers are running on the same machine, they are coexisting.
To support coexistence, you must either use the -setPorts and -resolvePortConflicts options when you migrate a profile or you must resolve port conflicts manually so that the two releases do not attempt to use the same ports. Any ports bound when the first profile starts will prevent the second profile from starting because the port is in use. No port changes are required if only one release of the profile is active at any given time.
For help in troubleshooting problems when migrating, read Troubleshooting migration.
About this task
For information on migrating to Version 9.0, read Migrating product configurations. For more information on coexistence among releases, read Running coexisting application servers.