According to the Performance Analysis Oracle 7.0 documentation, the middleware installation directory will require at least 4GB of free disk space for every monitored Oracle instance. We would like to reduce to 2GB of data file because it is none production environment.
4GB is a requirement in the 7.0 version. It is not possible to reduce this below 4 GB after the installation. Only if the install is performed in Demo mode can this be reduced.