About Domino server multiple installations
Multiple Domino server installations of same or different versions allow multiple Domino servers to run on a single computer. These versions can be standalone or partitioned or a combination of both. The advantages of using Domino partitioned servers are to reduce hardware expenses and minimize the number of computers to administer. Each Domino server installation has its own Domino data directory and notes.ini file.
The NetBackup for Lotus Notes agent uses different UNIX user account for each installation. When you use different accounts it is easier to use commands such as nsd to clean up orphaned processes after a Domino server crash. To accommodate this recommendation, It is possible to back up multiple Domino installations from a single NetBackup policy. However, each installation must be backed up by using a separate data stream.