ORA-16006: audit_trail destination incompatible with database open mode

on redhat 5.2 10gr2 (10.2.0.4) standby database.

while i was trying to open standby database got below error message

ORA-16006: audit_trail destination incompatible with database open mode

at little search on metalink found below note: ID 835638.1

solution:

SQL>alter system set audit_trail=OS scope=spfile;

SQL> startup force