Migration And Modernization Sequencing — Azure Solutions Architect (AZ-305)
Volume, Downtime, and Phase Signals in Migration
'Petabytes, offline transfer required' points to Azure Data Box, not DMS. 'Continuous replication, minimal cutover window' points to DMS online mode, not AzCopy. 'Assess dependencies before migrating' points to Azure Migrate, which is an assessment and orchestration platform, not a data movement tool. AzCopy handles bulk blob transfer between storage accounts. The constraint phrase in the scenario eliminates most distractors before any service comparison is needed. Read it first. Volume signals physical transfer. Downtime signals replication mode. Dependency signals assessment. Each phrase maps to exactly one tool. Apply that mapping before reading the answer options.
What This Pattern Tests
Azure migration sequencing questions test dependency-aware ordering for DevOps toolchain and application modernization. For AZ-400, migrating a CI/CD toolchain means moving source control (Azure Repos or GitHub) and package feeds (Azure Artifacts) before the build/release pipelines that consume them. For application migration, Azure Migrate assesses on-premises workloads, Azure Database Migration Service handles database replication with continuous sync, and Azure Site Recovery handles VM replication. The sequence follows data gravity: databases first (Azure SQL, Cosmos DB), application tier second (App Service, Container Apps), and presentation tier last (Static Web Apps, Front Door). The trap is migrating pipelines before their artifact sources are available in Azure, or migrating the web tier before the API it depends on.
Decision Axis
Dependency graph determines migration order: data stores and artifact repositories first, consumers and pipelines last.
Associated Traps
Decision Rules
Whether to use Azure Database Migration Service to migrate the SQL Server database tier to Azure SQL Managed Instance as Migration Wave 1 before the application servers move, versus collapsing all tiers into a single IaaS lift-and-shift wave with SQL Server on an Azure VM.
Whether to assign Azure Database Migration Service in online mode to the database tier as Wave 1 — before the web tier — or to use Azure Site Recovery for both tiers in a single wave, which both violates the dependency ordering constraint and replicates the SQL Server VM rather than migrating the database to a managed PaaS target.
Whether to replicate the NAS file server to an Azure VM using Azure Site Recovery (near-right IaaS rehost that preserves full operational overhead) or migrate content directly to Azure Blob Storage using an Azure Migrate-assessed transfer path (correct managed target that satisfies the CAF operational reduction mandate and respects wave-dependency ordering).
Whether to migrate the SQL Server tier to Azure SQL Managed Instance via Azure Database Migration Service online migration (satisfying wave-one dependency ordering, zero-downtime cutover, and managed-service overhead reduction) or to rehost SQL Server on Azure IaaS VMs via Azure Migrate (preserving familiar architecture but retaining full OS/patch management burden and violating the CAF modernization constraint).
Determine whether the shared file server should be rehosted to an Azure VM via Azure Site Recovery or migrated to a managed storage service in wave 1 before dependent tiers move, given the CAF constraint that post-migration operational overhead must be reduced.
Domain Coverage
Difficulty Breakdown