I've wondered about the licensing and how it works on multiple systems. Is the NE license for a single machine or number of users in use?

Essentially I want to set up a second system as a failover which is pulling the backups and restoring users to the second server. Can I use the same license info on both units or will my failover server need to be licensed separately?

Also, for archiving old users could I use a VM on the second system and run FOSS to move the to the archive server?