If you need to start shadow instance during upgrade process then you can use the following command.

Go to following directory for “SAP Version Upgrade”

/usr/sap/<SID>/SUM/abap/bin

or “Enhancement Package Upgrade”

/usr/sap/put/bin

To START the SHADOW Instance execute the following command ;

./SAPup startshd

To STOP the SHADOW Instance execute the following command ;

./SAPup stopshd

That’s it ….