AWS vs Azure Backup: A Practical Comparison of Database Backup and Disaster Recovery

Why database backup strategy matters

A single misconfigured retention policy or an untested restore procedure can turn a minor incident into a catastrophic data loss event. Organisations running production workloads on either AWS or Azure need to understand exactly what each platform provides out of the box - and where gaps remain that require additional configuration.

If your team is planning a cloud migration, backup architecture should be one of the first decisions you make. The cost of retrofitting backup policies after migration is significantly higher than designing them correctly from the start.

AWS database backup architecture

AWS offers multiple layers of backup protection for managed databases:

• AWS Backup - a centralised service that manages backup policies across RDS, Aurora, DynamoDB, EFS, and more from a single console
• RDS automated snapshots - daily full snapshots with transaction log backups every 5 minutes, enabling point-in-time recovery (PITR)
• Aurora backups - continuous backups to Amazon S3 with no performance impact, plus support for backtracking (rewinding the cluster without restoring)
• Cross-region replication - manual or automated copy of snapshots to a secondary AWS region for disaster recovery

The key advantage of AWS Backup is its ability to centralise backup governance. You define a backup plan once and apply it to resources across multiple accounts and regions using AWS Organisations integration.

Azure database backup architecture

Azure takes a more integrated approach where backup is tightly coupled with the database service itself:

• Azure Backup vault - a centralised management layer for backup policies, similar in concept to AWS Backup but with tighter integration into Azure Policy
• Azure SQL geo-redundant backup - automatic geo-replication of backups to a paired region, enabled by default on most tiers
• Point-in-time restore - granular recovery to any point within the retention window, typically with 5-10 minute RPO
• Long-term retention (LTR) - store full backups for up to 10 years for compliance requirements

Azure’s differentiator is that geo-redundancy is built into the default backup behaviour. You do not need to configure cross-region copy separately - it happens automatically when you select geo-redundant backup storage (GRS).

Feature comparison: AWS vs Azure backup

Retention policies and compliance

Both platforms support short-term and long-term retention, but the mechanisms differ significantly.

AWS retention model:

• RDS automated backups: 1-35 days retention
• AWS Backup vault lock: immutable backups for compliance (WORM - Write Once Read Many)
• Manual snapshots: retained indefinitely until explicitly deleted
• Cross-account backup: copy backups to isolated accounts for ransomware protection

Azure retention model:

• Short-term retention: 1-35 days for PITR
• Long-term retention (LTR): weekly, monthly, yearly backups stored up to 10 years
• Immutable vaults: prevent deletion of backup data before retention expiry
• Soft delete: 14-day recovery window for accidentally deleted backups

For organisations subject to regulations like GDPR, PCI DSS, or SOC 2, Azure’s built-in LTR policies are simpler to configure. On AWS, achieving similar long-term retention requires combining AWS Backup lifecycle rules with S3 Glacier transitions.

Cost comparison

Azure generally offers more cost-effective geo-redundant backup because GRS replication is included in the base backup storage price. On AWS, cross-region replication incurs separate data transfer charges that can add up for large databases. If you are evaluating total migration costs, our guide on cloud migration costs covers the full picture including licensing considerations.

Encryption and compliance

Both platforms encrypt backups by default, but the key management options differ:

AWS encryption:

• RDS encryption uses AWS KMS (Key Management Service)
• Encrypted instances produce encrypted snapshots automatically
• Cross-account key sharing via KMS key policies
• AWS CloudTrail logs all backup and restore operations

Azure encryption:

• Transparent Data Encryption (TDE) with service-managed or customer-managed keys
• Azure Key Vault integration for BYOK (Bring Your Own Key) scenarios
• Azure Monitor and Defender for Cloud provide compliance dashboards
• Backup data encrypted at rest using platform-managed keys by default

For organisations requiring HSM-backed keys, AWS offers CloudHSM integration while Azure provides Managed HSM within Key Vault. Both approaches satisfy most compliance frameworks including SOC 2, ISO 27001, and HIPAA.

Terraform configuration examples

AWS Backup plan with cross-region copy

resource "aws_backup_vault" "primary" {
  name        = "production-db-vault"
  kms_key_arn = aws_kms_key.backup.arn

  tags = {
    Environment = "production"
    ManagedBy   = "terraform"
  }
}

resource "aws_backup_vault" "dr_region" {
  provider    = aws.dr_region
  name        = "dr-db-vault"
  kms_key_arn = aws_kms_key.backup_dr.arn
}

resource "aws_backup_plan" "rds_daily" {
  name = "rds-daily-backup-plan"

  rule {
    rule_name         = "daily-backup"
    target_vault_name = aws_backup_vault.primary.name
    schedule          = "cron(0 3 * * ? *)"

    lifecycle {
      cold_storage_after = 30
      delete_after       = 365
    }

    copy_action {
      destination_vault_arn = aws_backup_vault.dr_region.arn

      lifecycle {
        delete_after = 90
      }
    }
  }
}

resource "aws_backup_selection" "rds_instances" {
  iam_role_arn = aws_iam_role.backup.arn
  name         = "rds-production-databases"
  plan_id      = aws_backup_plan.rds_daily.id

  selection_tag {
    type  = "STRINGEQUALS"
    key   = "BackupPolicy"
    value = "daily"
  }
}

Azure Backup for SQL Database with geo-redundancy

resource "azurerm_recovery_services_vault" "backup" {
  name                = "production-db-vault"
  location            = azurerm_resource_group.main.location
  resource_group_name = azurerm_resource_group.main.name
  sku                 = "Standard"

  soft_delete_enabled = true

  tags = {
    environment = "production"
    managed_by  = "terraform"
  }
}

resource "azurerm_backup_policy_vm" "daily" {
  name                = "daily-backup-policy"
  resource_group_name = azurerm_resource_group.main.name
  recovery_vault_name = azurerm_recovery_services_vault.backup.name

  backup {
    frequency = "Daily"
    time      = "03:00"
  }

  retention_daily {
    count = 35
  }

  retention_weekly {
    count    = 12
    weekdays = ["Sunday"]
  }

  retention_monthly {
    count    = 12
    weekdays = ["Sunday"]
    weeks    = ["First"]
  }

  retention_yearly {
    count    = 3
    weekdays = ["Sunday"]
    weeks    = ["First"]
    months   = ["January"]
  }
}

resource "azurerm_mssql_database" "production" {
  name                                = "production-db"
  server_id                           = azurerm_mssql_server.main.id
  sku_name                            = "GP_Gen5_4"
  geo_backup_enabled                  = true
  short_term_retention_policy {
    retention_days           = 35
    backup_interval_in_hours = 12
  }

  long_term_retention_policy {
    weekly_retention  = "P4W"
    monthly_retention = "P12M"
    yearly_retention  = "P3Y"
    week_of_year      = 1
  }
}

Which to choose: a practical decision framework

The right platform depends on your organisation’s specific requirements. Use this framework to guide your decision:

Choose AWS Backup when:

• You are already running workloads across multiple AWS accounts and need centralised governance via AWS Organisations
• You require fine-grained control over backup windows and maintenance schedules
• Your disaster recovery strategy involves cross-region replication with granular lifecycle policies
• You need to back up heterogeneous workloads (RDS, DynamoDB, EFS, EC2) under a single policy

Choose Azure Backup when:

• You need geo-redundant backup with minimal configuration (enabled by default)
• Long-term retention up to 10 years is a regulatory requirement
• Your organisation uses Azure Active Directory extensively and benefits from native integration
• You prefer a simpler operational model where backup “just works” without additional service configuration

Consider a multi-cloud backup strategy when:

• You have workloads split across both providers
• Regulatory requirements mandate geographic diversity beyond a single provider’s regions
• You need vendor-independent backup validation for audit purposes

For teams building scalable infrastructure with Terraform, the Terraform examples above provide a starting point you can extend. If you need ongoing management of backup policies alongside monitoring, patching, and incident response, a cloud retainer engagement ensures your backup strategy stays current as your infrastructure evolves.

Key takeaways

• AWS provides more granular control and centralised governance across accounts, making it ideal for complex multi-account environments
• Azure offers simpler geo-redundancy out of the box and more straightforward long-term retention configuration
• Both platforms encrypt backups by default and integrate with their respective key management services
• Cost differences are most significant for cross-region replication - Azure includes it in GRS pricing while AWS charges separately
• Terraform enables consistent, auditable backup configuration on either platform

Not sure which approach fits your organisation? Our consulting team can assess your current backup posture and design a resilient strategy tailored to your compliance requirements and budget.

Frequently asked questions

Is AWS Backup or Azure Backup better for database disaster recovery?

Azure Backup provides geo-redundant storage by default, making basic disaster recovery simpler to configure. AWS Backup offers more granular cross-region copy rules and lifecycle policies, which is better suited for complex multi-account environments with specific RPO/RTO requirements.

How does AWS RDS backup retention compare to Azure SQL backup retention?

Both AWS RDS and Azure SQL support 1-35 days of short-term retention for point-in-time restore. Azure SQL additionally offers built-in long-term retention (LTR) up to 10 years. On AWS, equivalent long-term retention requires AWS Backup lifecycle rules with cold storage transitions.

Which is cheaper for cross-region database backup - AWS or Azure?

Azure is generally more cost-effective for cross-region backup because geo-redundant storage (GRS) includes replication in the base price. AWS charges separate data transfer fees for cross-region snapshot copies, which can be significant for large databases.

Can I manage AWS and Azure database backups with Terraform?

Yes. Both AWS Backup and Azure Recovery Services Vault are fully supported by their respective Terraform providers. This allows you to define backup plans, retention policies, encryption settings, and cross-region replication as code, ensuring consistent and auditable backup configuration.

What are the main feature differences between AWS Backup and Azure Backup?

AWS Backup offers centralised multi-account governance via AWS Organisations, configurable backup windows, and fine-grained lifecycle policies with cold storage transitions. Azure Backup provides geo-redundancy by default (GRS), built-in long-term retention up to 10 years, soft delete protection, and simpler out-of-the-box configuration. The choice depends on whether you need granular control (AWS) or simpler operational defaults (Azure).

Need help designing your backup strategy?

Whether you are running on AWS, Azure, or both - getting backup architecture right from day one saves significant cost and risk down the line. Our team has implemented backup and disaster recovery solutions for organisations across finance, healthcare, and SaaS.

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