After doing a system copy/change hostname/change instance number, you find that your old / inactive SAP instance still appear in ST06 as depicted below and you want to remove it permanently.
|Unused / inactive SAP instance|
1. You can easily remove it from transaction RZ21 -> Topology -> Display Overview.
|Display Overview – RZ21|
2. Select unused / inactive SAP instance and press delete button.
|Delete unused / inactive SAP instance|
3. Now you don’t find unused / inactive SAP instance anymore from ST06.
|Inactive SAP instance is removed|
4. Check also from SM61 and make sure no inactive SAP instance appears.
|Remove inactive SAP instance|