Migrating from Azure to OCI

Azure and Oracle Cloud Infrastructure have an unusually close relationship for two competing clouds. They are directly interconnected, and Oracle database services run inside Azure data centres under arrangements designed to let customers use both. That changes the migration conversation: moving Oracle workloads from Azure to OCI is sometimes less about leaving Azure entirely and more about putting the database where it runs best while keeping the rest where it is.

This article explains how to approach an Azure to OCI migration, how the interconnect changes your options, what maps cleanly, and how to sequence the work.

The interconnect changes the calculus

The defining feature of the Azure and OCI relationship is the low latency interconnect between the two clouds, and the availability of Oracle database services within Azure regions. This means you are not forced into an all or nothing decision. You can keep your application tier on Azure, where it may integrate tightly with other Azure services, while running the Oracle database on OCI or on the Oracle service inside Azure, connected over the interconnect.

For many organisations this multicloud posture is the destination rather than a transitional state, and it is worth deciding up front whether your goal is a full migration to OCI or a split estate. Our guide to multicloud and hybrid workloads explores the split model in more depth.

The case for moving Oracle workloads

As with AWS, the strongest case for moving to OCI is for Oracle Database workloads. Licensing Oracle software on a third party cloud and running it on general purpose infrastructure is often more expensive than running it on OCI with Bring Your Own Licence or on an engineered service such as Autonomous Database or Exadata Cloud Service. For database heavy estates, this is where the economics shift.

The corollary is that you should be selective. Workloads that are deeply integrated with Azure services and carry no heavy Oracle licensing may be perfectly happy where they are. Focus the migration effort where it changes the numbers, and validate that with the cost modelling in our guide to OCI migration cost estimation.

Service mapping from Azure to OCI

Like any cloud to cloud move, much of the work is mapping services to their equivalents. The table shows the common mappings between Azure and OCI.

One area worth special attention is identity. Many Azure estates centre on Entra ID for authentication, and rather than rebuild identity on OCI you typically federate, letting users keep their existing credentials while OCI trusts the Azure identity provider. This is usually cleaner than recreating accounts and is well supported.

Using the interconnect during migration

The interconnect is not just an end state, it is a migration asset. During the move you can use the low latency link to keep workloads talking across the two clouds while you transition them one at a time. A database can run on OCI while its application still sits on Azure, with acceptable performance over the interconnect, which gives you flexibility in how you sequence the work.

This is a genuine advantage over a more isolated cloud to cloud move, because the strong connectivity removes much of the latency anxiety that usually forces tightly coupled systems to move together in a single window.

Lift and shift or re platform?

The same choice applies as in any migration. You can lift and shift Azure virtual machines to OCI Compute quickly and at low risk, or re platform Oracle databases onto Autonomous Database to capture more value over a longer timeline. The trade offs are the same ones we set out in our guide to lift and shift versus re platform on OCI, and the pragmatic pattern of lifting first then re platforming selectively applies here too.

Identity, governance and the split estate

Running a split estate across Azure and OCI raises governance questions that a single cloud avoids. Identity is the first. Federating OCI with Entra ID keeps a single source of truth for who your users are, but you still have to design how roles and entitlements map across the two clouds so that access stays consistent and auditable. Decide this deliberately rather than letting two parallel access models drift apart.

Cost visibility is the second. With spend spread across two providers, you need a way to see the whole picture rather than reconciling two separate bills by hand. Establish tagging and cost reporting that span both clouds from the start, so the multicloud estate does not become a place where spend quietly hides. This is exactly the kind of discipline an independent cost review brings, and it matters more, not less, when the estate is split.

Security posture is the third. The controls you rely on in Azure have OCI equivalents, but they are configured differently, and a control that is strong on one side can be absent on the other if nobody maps it across. Treat the security baseline as something you define once and implement on both clouds, so the split estate does not become a weakest link problem.

A phased plan

Sequence the migration in waves, prioritising the Oracle database workloads where the savings are largest and the platform fit is best. Keep the Azure side running and use the interconnect to bridge the estate during the transition, validating each wave on OCI before moving the next. The method mirrors the approach in our guide to migrating from AWS to OCI, with the interconnect giving you extra flexibility on sequencing.

An Azure to OCI migration is often the gentlest of the cloud to cloud moves, precisely because the two platforms were built to work together. Used well, it lets you put each workload where it runs best without a wholesale upheaval. An independent cost optimization review can confirm the savings are real before you commit, and for the full journey, start from the complete guide to Oracle Cloud migration.