There are a few migration combinations that can be considered local migration depending on the availability of the environment being migrated. At a minimum, you have two distinctive options with this migration path. You can perform a local migration taking offline the source environment or you can maintain both source and target environments coexisting. Depending on the migration path you choose, there might be additional factors to consider
Generally, local migration without coexistence is probably the simplest scenario. Both source and target WebSphere® Portal Express® installations are on the same machine and resource conflicts are minimal.
There are still some directory structure considerations to keep in mind. You might want to use the same directory structure in you new WebSphere Portal Express installation to hold logs and backups for example.
Other configurations such as ports or virtual portals for example should not conflict. Both, source and target WebSphere Portal Express will not be running in parallel at the same time.
Coexistence is the process of running both, the original and the newly migrated WebSphere Portal Express servers on the same machine at the same time. This approach allows for maintaining your current production environment online while at the same time performing the migration to a newer version of WebSphere Portal Express. This statement is not exclusive of local migration with coexistence, you can also achieve this by performing a remote migration.
When planning migration with coexistence you need to consider the hardware and software requirements for the new version of WebSphere Portal Express. Make sure the machine currently running your production WebSphere Portal Express has enough resources to handle the new installation.
As you have two installations of WebSphere Portal Express you need to carefully plan to avoid resource conflicts. Default settings like port assignments require updating on the migrated WebSphere Portal Express.