Do you know what happens when you enable zonal redundancy for your SQL managed instance?

Lets define it first (in the context of Business-Critical tier) – zonal redundancy is achieved by placing compute and storage replicas in different availability zones (3) and then using underlying Always On availability group to replicate data changes from the primary instance to standby replicas in other availability zones. Key take away here. It will use 3 zones, if you do not enable this setting it will NOT! Diagrams will show this easier – below shows some examples for BC (Business Critical).

What’s the point? Zonal redundancy greatly improves the availability and disaster resilience of your SQL Managed Instance by protecting against the loss of an entire Availability Zone, not just individual hardware or racks. This is especially important for mission-critical applications that require the highest possible uptime within a region.

Default Setup

To 3 availability zones

Quite a big difference if you ask me. You can do this for general purpose too (the concept of zone redundancy) but it is in preview mode so I would be cautious with that, this is also available in select regions right now. You can configure this via Azure portal, CLI or PowerShell. See this guide on the how to do. https://learn.microsoft.com/en-us/azure/azure-sql/managed-instance/instance-zone-redundancy-configure?view=azuresql&tabs=azure-portal

So, if you want protection greater than 1 zone for your important apps – This is the way.