The target server is installed in the same installation location as the source server. You can choose to perform this type of upgrade if you wish to install the configuration (that is, the domains) in the same location as before. In this scenario, you install the binaries in the same location as the existing binaries using the installer.
For an in-place upgrade from Sun Java System Application Server 9.1, 9.1 Update1, 9.1 Update 2 to Enterprise Server 2.1, do not use the asupgrade utility. It is sufficient to upgrade the runtime binaries by using the installer. After upgrading the binaries to Enterprise Server 2.1, start the domain with the asadmin start-domain command.
An in-place upgrade involves the following sequence of tasks:
To Upgrade Remote Node Agents (In-place) (only if you have remote agents in the source application server).
If all existing node agents (from the source application server installation) run on a single machine, the upgrade tool automatically detects node agents, if any, on the source installation.