SAP Basis Basics Part 3

1901463 — How to unlock the SAP system to perform correction(s) during an upgrade.

To unlock the SAP system, enter the following commands (here <transport_profile> or DEFAULT.TPP is the transport profile of the transport domain to which the system is connected): The system may be either the original SAP system or the shadow system, depending on which one the error occurred.
Original SAP system
cd \<update directory>\abap\exe
tp unlocksys <SAPSID> pf=..\var\DEFAULT.TPP
tp unlock_eu <SAPSID> pf=..\var\DEFAULT.TPP
Shadow system
cd \<update directory>\abap\bin
SAPup unlockshd
Log on to the SAP system or shadow system and correct the error.
To lock the original SAP system or shadow system again, enter the
following commands:
Original SAP system
cd \usr\sap\abap\exe
tp lock_eu <SAPSID> pf=..\var\DEFAULT.TPP
tp locksys <SAPSID> pf=..\var\DEFAULT.TPP
Shadow system
cd \<update directory>\abap\bin
SAPup lockshd