question

There are a couple of options depending on your needs. Each one would offer different levels of RPO/RTO so I would evaluate them to ensure they meet your business needs. 1. Mirroring without a witness. This would not be an automatic failover. 2. Traditional clustering (Active/Passive). This would be an automatic failover. 3. Availability groups with a non-readable secondary. 4. Log shipping. This would not be an automatic failover. I believe these can be implemented with a single license as long as the secondary (DR) isn't been used for any production processing, IE: reporting or active workloads. However, I would definitely want to confirm that with your licensing vendor. They would have the resources to double check that. If you do have to fail over, however, you might have to move licenses around in order to be compliant. Also consider having software assurance for the licensing. This, I think, would give you the best options as per the article below. https://blogs.technet.microsoft.com/volume-licensing/2013/08/22/licensing-how-to-sql-server-fail-over-vs-cold-disaster-recovery-rights/ Also, keep in mind that you will actually license for the latest version so I would recommend looking at 2016 instead of 2012. Hope that helps!