When we talk about Disaster Recovery or DR, it’s often coupled with the term High Availability or HA. Here are some definitions from my graduate course on HADR.
- Deals with minor outages, and failover solutions are automated
- The goal is to restore full system functionality in a short time
- Deals with major outages such as natural and man-made disasters
- Focuses on manual processes and procedures to restore systems back to their original state
- Characterized by a phased approach to restoring the primary site
In the context of SQL Server, HA would be Availability Groups (AG), Failover Clustering (FCI), Log Shipping and more. I won’t be addressing High Availability in this post, however.
Chrissy has a demo of everything in action, including running a series of tests to ensure that your DR site actually has everything.