Unnecessary Use of RA-GRS for Azure SQL Backup Storage

Balazs Engedi

CER:

Azure-Databases-2089

Service Category

Databases

Cloud Provider

Azure

Service Name

Azure SQL

Inefficiency Type

Inefficient Configuration

Explanation

Azure SQL databases often use the default backup configuration, which stores backups in RA-GRS storage to ensure geo-redundancy. While suitable for high-availability production systems, this level of resilience may be unnecessary for development, testing, or lower-impact workloads.

Using RA-GRS without a business requirement results in avoidable costs. Downgrading to LRS or ZRS — where appropriate — can significantly reduce monthly backup storage spend. This change has no impact on backup frequency or retention behavior, only the underlying storage replication method.

Relevant Billing Model

Backup storage is charged based on GB/month
RA-GRS storage is the default and most expensive option
LRS (Locally Redundant Storage) and ZRS (Zone Redundant Storage) are lower-cost alternatives
Changing backup storage tier can reduce backup costs by up to 50% without affecting primary database performance

Detection

Review backup redundancy settings for Azure SQL databases
Identify databases with RA-GRS enabled by default
Determine whether geo-redundant backup storage is a business or compliance requirement
Validate whether LRS or ZRS would be sufficient based on workload criticality and risk tolerance

Remediation

For non-critical or non-regulated workloads, change the backup redundancy setting to LRS (or ZRS where supported)
Document any exceptions where RA-GRS must be retained for compliance
Incorporate backup configuration reviews into provisioning and governance processes
Monitor backup storage cost trends following changes to confirm savings

Relevant Documentation

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