You have SQL Server on an Azure virtual machine. The databases are written to nightly as part of a batch process. You need to recommend a disaster…

Azure Site Recovery (ASR) is the optimal solution as it meets all specified requirements. It is designed for disaster recovery to a secondary Azure region, fulfilling the regional outage requirement. ASR's recovery plans enable automated failover, which can achieve a Recovery Time Objective (RTO) of 15 minutes. The replication frequency can be configured to easily meet the 24-hour Recovery Point Objective (RPO). Compared to maintaining a fully configured and licensed secondary SQL Server for an availability group, ASR is more cost-effective, as the resources in the disaster recovery region are not fully provisioned until a failover occurs, thus minimizing costs.

A. Azure virtual machine availability sets: These provide high availability within a single Azure region by protecting against local hardware failures, not regional outages.

B. Azure Disk Backup: While this can meet the RPO, its RTO is typically measured in hours, not minutes, and it does not provide an automated failover mechanism.

C. an Always On availability group: This solution is more complex and expensive than necessary. Given the high 24-hour RPO, the cost of a second SQL Server license and compute is not justified.

1. Azure Site Recovery Documentation: "Azure to Azure disaster recovery architecture". This document outlines how ASR replicates Azure VMs to a secondary region for disaster recovery. Under the "Recovery Time Objective (RTO)" section

it states

"Site Recovery has an RTO of a couple of hours... For very low RTOs

you can use recovery plans... and bring up an application stack in minutes." This supports the 15-minute RTO requirement with automation.

2. Azure Site Recovery Documentation: "About Site Recovery". This overview explicitly states ASR's purpose: "Orchestrates replication of Azure VMs between Azure regions... for business continuity and disaster recovery (BCDR)." This confirms its suitability for regional outages.

3. Azure Availability Sets Documentation: "Availability options for Azure Virtual Machines". This document clarifies the scope of availability sets: "An availability set is a logical grouping of VMs that allows Azure to understand how your application is built to provide for redundancy and availability... protecting you from hardware failures within a datacenter." This confirms they are not for inter-region DR.

4. Azure Backup Documentation: "Restore Azure virtual machines". The restore process involves multiple steps (selecting restore point

choosing restore type

etc.)

which makes achieving a 15-minute RTO with automated failover unfeasible compared to ASR.