Greetings, We are looking at implementing dataguard, 10.2.0.3.0 Enterprise Edition Oracle on Red Hat Linux. The question has been raised as to whether the O/S version must be the same on the primary and the standby. If the primary were to run RHEL4 and the standby were to be running RHEL5 would that create problems? I have not found any documentation indicating a requirement that the O/S be at the same release. Thanks. Bill Wagman Univ. of California at Davis IET Campus Data Center wjwagman@xxxxxxxxxxx (530) 754-6208 -- //www.freelists.org/webpage/oracle-l