Comment by tinus_hn

Then you would have to rewind the tape at the end, which is not what you want. You want to write the tape and keep it at that position and be done.

If you write the catalog at the end, you have to rewind and read the whole tape to find it and read it. Which is not an improvement over reading the tape and reconstructing it.

This is all either impossible or very difficult to fix when there is actually not a problem, if there is a disaster and the database is lost, you just read the tapes to reconstruct it.