Zone-redundant
What it is
Zone-redundant describes a supported Azure resource that the service distributes or replicates across multiple availability zones in one region. It is a behavior of a particular service and configuration, not a separate place that you deploy to.
In plain language: instead of Northwind putting all copies of something in one building, the service keeps usable copies in more than one building and switches away from a failed building for it.
How it differs from zonal
A zonal resource sits in one chosen zone. A zone-redundant resource spans zones. Both terms require that the region and service support availability zones; individual services can require a particular SKU, tier, or configuration.
Northwind example
Northwind chooses zone-redundant storage for order files. Azure Storage maintains copies across availability zones in the primary region. Northwind does not pick “zone 1 for copy A” or operate the replication. In contrast, for two zonal application VMs, Northwind chooses separate zones and configures the load balancer and failover behavior itself.
What it does not mean
- It does not mean the resource is protected from a full regional outage; use a multi-region recovery design when that risk matters.
- It does not mean every application dependency is redundant. A resilient front end can still fail if its only database or identity dependency fails.
- It does not replace backups. A deletion or corrupt update can replicate between zones.
Sources and re-audit
- Microsoft Learn — What are availability zones?, checked 2026-09-16.
- Microsoft Learn — Azure Storage redundancy, checked 2026-09-16.
Related
availability-zones · redundancy-lrs-zrs-grs · managed-disks · load-balancer · azure-backup