I had was told I need an exact identical copy of our Oracle 11.2.0.3 database server running on Linux for testing. This seemed smart so I stood up an identical copy of the O.S. and loaded 11.2.0.3 as well as a backupset from my production server to the new test server. My question is can both the original production Oracle and the new testing Oracle database both have the same identical SID = orldb?

Will this be bad? I read the manual and understood that as long as both instances use separate SGA's on completely separate systems, there is no issue what so ever. And since we don't need them to be unique or fail over, we could keep them as similar as possible.

Thanks for any input and or advice!

same SID can exist on different servers

But if you are connecting to both of them from the same machine, the name in tnsnames must be different.

Usually the problem is not the SID (apart from possible confusion) but the DBID.

If you have 2 (or more) databases with the same DBID you will face big problems i.e. maintaining a RMAN catalog database (the DBID is the primary key for the backup environment there).

It's also possible, that you run into troubles with Grid Control (I've never tried that)

You may, however, easily change the DBID (as well as the SID, if needed) with the Oracle "DBNEWID " utility.