If an instance with this name already exists, the program asks if you wish to upgrade it.
Note:
If you select an existing instance that is of the same InterSystems IRIS version as the installation kit, the installation is considered an upgrade, and you can use the Custom selection, described in the following step, to modify the installed client components and certain settings.
The InterSystems IRIS registry directory, /usr/local/etc/irissys, is always created along with the InterSystems IRIS installation directory.