Feb 21, 2018 - 07:23 AM
2. Multiplexing - one CAL required per user - see Microsoft terms on this.
3. Microsoft MAP toolkit can do this I believe, as can other SAM tools. Make sure you don't just count the number of users who've logged on to the server via RDC or similar.
4. Maximum in a 90-day period, with some exceptions (e.g. permanently decommissioned hardware, terminated employee)
5. As above
6. Don't need a CAL
7. SQL Server has limited failover rights as a Software Assurance benefit. OS does not (except for DR testing - a limited number of days per year). For each SQL Server license with SA you can run a mirror server, as long as that server isn't doing any work or serving users. Active/Passive failover pair.
8. SQL Server is licensed per core or per Server/CAL, not per instance. So a correctly licensed server (e.g. all physical cores licensed) can host multiple instances.
Source: Microsoft Product Terms and Licensing Guides