On-Prem Datacenter to Azure Blueprint
An Azure-targeted datacenter exit built on the Cloud Adoption Framework. Enterprise-scale landing zones, Azure Migrate replication, and Database Migration Service drive wave-based rehosting, followed by containerization and identity modernization.
What and Why
This blueprint moves on-premises servers and applications to Microsoft Azure following the Cloud Adoption Framework (CAF). Organizations choose Azure for tight integration with existing Windows Server, Active Directory, and Microsoft 365 estates, plus Azure Hybrid Benefit licensing savings. The plan rehosts first to hit datacenter-exit deadlines, then modernizes.
Phases
Assessment. Run Azure Migrate to discover servers, dependencies, and SQL and web apps. It produces right-sizing and cost estimates and Azure SQL readiness reports. Classify workloads by 7 Rs disposition.
Landing zone. Deploy CAF enterprise-scale landing zones: a management group hierarchy, hub-and-spoke networking with Azure Firewall, ExpressRoute or VPN back to on-prem, Azure Policy guardrails, Log Analytics, and Microsoft Entra ID. Provision with Terraform or Bicep.
Migration waves. Use Azure Migrate Server Migration (agentless or agent-based replication) to rehost VMs. Migrate databases with the Azure Database Migration Service to Azure SQL Managed Instance or Flexible Server. Test each wave in a non-production subscription before cutover.
Modernization. Containerize suitable apps to Azure Kubernetes Service or App Service, move file shares to Azure Files, and adopt managed identity to retire stored credentials.
Decommission. Validate backups and run a soak period, then retire on-prem hosts and reclaim licenses.
Key Risks and Mitigations
- Identity sprawl during AD migration. Use Entra Connect and least-privilege RBAC from day one.
- Replication lag over constrained links. Seed bulk data with Azure Data Box and use ExpressRoute for sync.
- Cost surprises from oversized VMs. Apply Azure Advisor right-sizing, reservations, and Hybrid Benefit.
- Operational unfamiliarity. Build runbooks and enable teams on Azure Monitor before cutover.
Recommended Tooling
Azure Migrate and Database Migration Service, CAF landing-zone accelerators, Terraform or Bicep, Azure Monitor with Log Analytics, and Azure Backup and Site Recovery.
Success Metrics
Measure cost reduction against the on-prem baseline, servers migrated per wave, post-cutover availability, and lead time for new environment provisioning.
Prerequisites
An Azure tenant and CAF landing zone, network connectivity (ExpressRoute or VPN), an Azure Migrate assessment, and a wave plan with rollback criteria.