Getting locked out of a SQL Server instance can happen due to a number of situations. The most common scenario I’ve encountered is when a SQL Server is moved from one domain to another without the domain being trusted or having a local SQL admin account. I recently encountered another incident where a DBA was attempting to fail over a log-shipped instance to another instance. Part of their run book included a script to disable a set of users to block production access to the instance. The problem was, the production instance was on a cluster, unlike the development and QA systems where the script had been tested. Disabling the users in production took down the instance preventing the tail log backups from occurring. We had to get the instance back up in order to take those final backups.
What can you do if you find that you’re locked out of a SQL Server instance?
Read on for that answer.