My course virutal systems did not behave the way the video showed. I had two issues.
1. While PIINT1 has N-way buffering, it owns the tags in the OPC interface and is updating them on both servers. After stopping the interface on PIINT1, and starting it on PIINT2, the second interface got this error for each tag: Error -11414, Buffered point does not accept new events. I can reset the buffered tag list on the registration using piartool -bfs 1 -reset to clear the ownership.
2. After clearing this error, my PIINT2 OPC-DA interface starts without errors, however it only updated points on PISRV2, but not on PISRV1.
Therefore, I'm somewhat stuck here and would like to remedy things before moving to the failover section.