For reference, as I know I'll need this again before too long …
This is how I can stop the DB2 Administration Server and DB2 instance without needing to explicitly log in as a DB2 user: -
su - -c "db2admin stop" dasusr1
su - -c "db2stop" db2inst1
So that's all good then :-)
su - -c "db2stop" db2inst1
So that's all good then :-)