There have been some changes in the way that z/Server is configured and works.
One change is that the z/Server client now uses technology from Micro Focus Mainframe Access (MFA) Server, so you must install MFA Server on the host before you can install and use z/Server. See Installing Mainframe Access Server and Configuring and Administering the Mainframe for more information.
If you are upgrading from z/Server V2R2M02 or earlier you will also have to make changes to several JCL members and customize a single REXX procedure.
The migration that you need to perform depends on whether you want to continue to use your legacy configuration files or switch to use the XML configuration file. If you want to continue using your legacy configuration files you only need to perform the steps described in Basic migration. If you want to switch to use the XML configuration file, perform the steps described in Basic migration as well as those in Additional migration to use the XML configuration file.