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AZ-305 Business Continuity solutions

April 29, 2025•1817 words•10 min read•
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AZ-305 Azure Solutions Architect Expert

Azure Recommendations for Business Continuity Solutions

Below are the recommended Azure solutions for data storage as aligned with the AZ-305 exam objectives.

Design Solutions for Backup and Disaster Recovery

1. Recommend a Recovery Solution for Azure/Hybrid Workloads

Azure Site Recovery (ASR)

  • Use Case: Orchestrates replication, failover, and failback of Azure VMs, on-premises VMware/Hyper-V VMs, and physical servers.
  • Hybrid Workloads:
    • Replicate on-premises VMs to Azure for disaster recovery (DR).
    • Automate recovery plans with multi-VM consistency for apps spanning multiple VMs.
  • Recovery Objectives:
    • RPO: As low as 5 minutes (continuous replication).
    • RTO: Minutes with automated failover123.

Azure Backup

  • Centralized Management: Protects Azure VMs, on-premises files/folders (via MARS agent), SQL/PostgreSQL databases, SAP HANA, and Azure Blobs.
  • Hybrid Support:
    • Use Azure Backup Server (MABS) or DPM for on-premises VMware/Hyper-V VMs.
    • Long-term retention (up to 10 years) for compliance453.

Best Practices:

  • Combine ASR for VM failover and Azure Backup for granular file/database recovery.
  • Use Azure Arc to extend Azure management to on-premises servers for unified policy enforcement56.

2. Recommend a Backup/Recovery Solution for Compute

Azure VM Backup

  • Application-Consistent Snapshots: Ensures data integrity for apps like SQL Server73.
  • Managed Disk Backups:
    • Locally Redundant Storage (LRS): Protects against rack/drive failures.
    • Zone-Redundant Storage (ZRS): Tolerates zonal outages28.
  • Restore Options: Full VM restore, individual files, or disks.

Best Practices:

  • Enable Soft Delete and Resource Locks to prevent accidental deletion.
  • Use Azure Policy to enforce backup compliance across subscriptions79.

3. Recommend a Backup/Recovery Solution for Databases

Azure SQL Database/Managed Instance

  • Automated Backups:
    • Full weekly + differential every 12 hours + log backups every 10 minutes.
    • Point-in-Time Restore (PITR): Up to 35 days retention (extendable to 10 years with LTR)1011.
  • Azure Backup for SQL:
    • Application-consistent backups for SQL Server on Azure VMs3.

Cosmos DB

  • Continuous Backups: 7-day retention with 1-second granularity for NoSQL/API for MongoDB.

Best Practices:

  • For mission-critical SQL workloads, use Business Critical tier with built-in Always On availability groups1213.

4. Recommend a Backup/Recovery Solution for Unstructured Data

Azure Blob Storage

  • Operational Backup:
    • Point-in-Time Restore: Recover from accidental deletes/corruption using soft delete and versioning9.
  • Vaulted Backup:
    • Offsite backups to a Recovery Services vault with custom retention policies914.

Azure Files

  • Snapshot Backups:
    • Schedule daily/weekly snapshots with Azure Backup.
    • Restore individual files or entire shares instantly15.

Data Lake Storage Gen2

  • Vaulted Backup (Preview): Replicate containers to a backup vault for regional outages14.

Best Practices:

  • Use Cool/Archive tiers for infrequently accessed data to reduce costs914.

Design for High Availability

1. Recommend a High Availability Solution for Compute

Virtual Machine Scale Sets (VMSS)

  • Autoscaling: Adjust instance count based on CPU/memory metrics.
  • Orchestration Modes:
    • Flexible: Distribute VMs across Availability Zones (99.99% SLA).
    • Uniform: Fault/update domain isolation within a zone (99.95% SLA)16.

Availability Zones (AZs)

  • Deploy VMs across 3+ zones for resilience against data center failures81718.

Best Practices:

  • Use Proximity Placement Groups to minimize latency for performance-sensitive apps86.

2. Recommend a High Availability Solution for Relational Data

Azure SQL Database/Managed Instance

  • Business Critical Tier:
    • Built-in Always On availability groups with synchronous replicas.
    • Zone-Redundant Configuration: Spread replicas across AZs (99.995% SLA)181213.

SQL Server on Azure VMs

  • Always On Availability Groups:
    • Deploy primary and secondary replicas across Availability Zones6.

Best Practices:

  • For cross-region HA, enable Auto-Failover Groups in Azure SQL1213.

3. Recommend a High Availability Solution for Semi/Unstructured Data

Azure Cosmos DB

  • Multi-Region Writes: Enable writes in 30+ regions with automatic failover (99.999% SLA).
  • Consistency Levels: Choose from "Strong" to "Eventual" based on app needs.

Azure Blob Storage

  • Redundancy Options:
    • ZRS: 99.9999999999% durability within a region.
    • GRS: Cross-region replication for geo-resiliency98.

Azure Files

  • Zone-Redundant Storage (ZRS): HA within a region.
  • Geo-Redundant Storage (GRS): DR across regions15.

Best Practices:

  • For analytics workloads, use Data Lake Storage Gen2 with ZRS/GRS and hierarchical namespace14.

Summary Table

RequirementAzure RecommendationKey Features
Hybrid Workload RecoveryASR + Azure BackupRPO 5 min, automated failover, MARS agent for on-premises
Compute BackupAzure VM Backup (application-consistent snapshots)LRS/ZRS redundancy, Soft Delete
Database BackupSQL Automated Backups + Azure Backup for SQL VMsPITR, 15-min RPO, LTR up to 10 years
Unstructured Data BackupBlob Storage (versioning/soft delete) + Azure Files BackupOperational/vaulted backups, cross-region restore
Compute HAVMSS (Flexible mode) + Availability Zones99.99% SLA, autoscaling
Relational Data HASQL DB Business Critical (zone-redundant) + Auto-Failover Groups99.995% SLA, cross-region failover
Semi/Unstructured HACosmos DB (multi-region writes) + Blob ZRS/GRS99.999% SLA, geo-redundancy

By aligning these recommendations, you ensure compliance with Azure’s SLAs and optimize for cost, performance, and resilience.

Summarised with Perplexity.

Footnotes

  1. https://n2ws.com/blog/microsoft-azure-cloud-services/disaster-recovery-plans-in-azure-site-recovery-a-practical-guide ↩
  2. https://learn.microsoft.com/en-us/azure/virtual-machines/backup-and-disaster-recovery-for-azure-iaas-disks ↩ ↩2
  3. https://learn.microsoft.com/en-us/azure/backup/backup-azure-sql-database ↩ ↩2 ↩3 ↩4
  4. https://azure.microsoft.com/en-in/solutions/backup-and-disaster-recovery ↩
  5. https://learn.microsoft.com/en-us/azure/backup/backup-overview ↩ ↩2
  6. https://learn.microsoft.com/en-us/azure/azure-sql/virtual-machines/windows/availability-group-overview?view=azuresql ↩ ↩2 ↩3
  7. https://n2ws.com/blog/vm-backup-in-azure-a-practical-guide ↩ ↩2
  8. https://learn.microsoft.com/en-us/azure/virtual-machines/disks-high-availability ↩ ↩2 ↩3 ↩4
  9. https://learn.microsoft.com/en-us/azure/backup/blob-backup-overview ↩ ↩2 ↩3 ↩4 ↩5
  10. https://n2ws.com/blog/microsoft-azure-cloud-services/azure-sql-database-backup-a-practical-guide ↩
  11. https://learn.microsoft.com/en-us/azure/azure-sql/managed-instance/automated-backups-overview?view=azuresql ↩
  12. https://docs.azure.cn/en-us/azure-sql/managed-instance/high-availability-sla-local-zone-redundancy ↩ ↩2 ↩3
  13. https://learn.microsoft.com/en-us/azure/azure-sql/managed-instance/sql-managed-instance-paas-overview?view=azuresql ↩ ↩2 ↩3
  14. https://learn.microsoft.com/en-us/azure/backup/azure-data-lake-storage-backup-overview ↩ ↩2 ↩3 ↩4
  15. https://learn.microsoft.com/en-us/azure/backup/azure-file-share-backup-overview ↩ ↩2
  16. https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/overview ↩
  17. https://www.linkedin.com/pulse/azure-availability-sets-vs-zones-williams-oke-omosayin ↩
  18. https://learn.microsoft.com/en-us/azure/azure-sql/database/media/high-availability-sla/zone-redundant-business-critical-service-tier.png?view=azuresql\&sa=X\&ved=2ahUKEwirwKyu6fyMAxWXwvACHQW3IDUQ_B16BAgEEAI ↩ ↩2

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