SQL Interview: 87 Mirrored backups

This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.

Section: Administration Level: Medium

Question:

What are mirrored backups?

Do they increase or decrease the reliability of backups?

Answer:

Mirrored backups cause the same backup data to be written to multiple locations.

They decrease the reliability of backups, because if writing to any location fails, all backups fail.

2025-10-19