Migrating from AWS to OCI

Plenty of organisations run Oracle databases and applications on AWS and quietly pay a premium for the privilege. Moving those workloads to Oracle Cloud Infrastructure can change the economics significantly, particularly for the licensing and performance of Oracle software. But a cloud to cloud migration has a different character to a move from on premises, and understanding that difference is the key to doing it well.

This article explains how to approach an AWS to OCI migration, what maps cleanly, where the real savings come from, and how to sequence the work.

The case for moving Oracle workloads off AWS

The strongest case for an AWS to OCI move is for Oracle workloads specifically. Oracle Database licensing on a third party cloud can be costly, and OCI offers licensing and platform options designed around Oracle software, including Bring Your Own Licence and engineered services such as Exadata Cloud Service and Autonomous Database. For an estate built heavily on Oracle, the recurring cost difference can be substantial.

That does not mean moving everything. Many organisations adopt a multicloud posture, keeping some workloads on AWS where they fit well and moving the Oracle estate to OCI where the economics favour it. We explore that model in our guide to multicloud and hybrid workloads, and the two clouds can even be linked directly for low latency interconnect.

Service mapping: what moves cleanly

A cloud to cloud migration is largely an exercise in mapping services. Most AWS primitives have a direct OCI equivalent, which makes much of the move mechanical. The table shows the common mappings.

The mappings are mostly clean, but two areas deserve care. Identity and access management uses a different model on OCI, so policies must be redesigned rather than translated literally. And storage performance tiers do not line up one for one, so match on measured performance rather than on the label.

Where the savings actually come from

The headline saving in an Oracle focused AWS to OCI move usually comes from two places: licensing and database platform. Running Oracle Database on OCI with a clean Bring Your Own Licence position, or on a service like Autonomous Database that bundles the platform, frequently costs less than the equivalent on AWS RDS or self managed on EC2.

Do not assume, though. Build a proper cost model that compares the real AWS spend against the projected OCI spend, including licensing, and validate it before you commit. Our guide to OCI migration cost estimation walks through how to build that model, and an independent cost optimization review can confirm the numbers are real.

Networking between and across the clouds

During the migration you will run in both clouds for a period, so plan the connectivity. You can connect AWS and OCI over a VPN, or via a private interconnect for lower latency and higher throughput. This link carries the data transfer and any traffic between workloads that have not yet moved and those that have.

Recreate the network topology thoughtfully on OCI rather than copying the AWS layout blindly. The two clouds structure virtual networks, security groups and routing differently enough that a literal copy tends to be both insecure and inefficient. Design the OCI virtual cloud network around the actual traffic flows.

Watch the egress and the data gravity

One cost that surprises teams moving off AWS is data egress. Pulling large volumes of data out of AWS incurs egress charges, and for a data heavy migration that one off cost can be material. Factor it into the project budget rather than discovering it on the final invoice, and where possible structure the transfer to minimise repeated movement of the same data.

The deeper issue is data gravity. The system that holds the data tends to pull the systems that use it towards the same cloud, because crossing a cloud boundary on every query adds latency and cost. This is why, in a multicloud end state, you generally want an application and its database on the same side of the boundary. When you plan which workloads move and which stay, follow the data: move the things that talk to the migrated database alongside it, and leave genuinely independent workloads where they are.

Egress and data gravity together argue for moving coherent groups of systems rather than scattering the migration across loosely related workloads. The dependency map you built during assessment is what tells you where those natural groupings lie, so that each wave moves a self contained slice with its data and the applications that depend on it.

Lift and shift or re platform?

As with any migration, you choose between moving workloads as they are and reshaping them for the target. A straight lift and shift of EC2 instances to OCI Compute is fast and low risk, and it is often the right first move. Re platforming, for example moving from self managed Oracle on EC2 to Autonomous Database, captures more value but takes longer. We compare the trade offs in our guide to lift and shift versus re platform on OCI.

A common and pragmatic pattern is to lift and shift first to capture the licensing and platform savings quickly, then re platform selected workloads afterwards once they are stable on OCI. This decouples the urgent cost win from the slower modernisation work.

A phased approach

Sequence an AWS to OCI migration in waves, starting with lower risk workloads to prove the path before you move the crown jewels. Use the dependency map to keep tightly coupled systems together, and keep the AWS side running until each wave is validated on OCI. The discipline is identical to any other migration, and the broader method is in our guide to migrating from Azure to OCI, which shares most of the same principles.

Cloud to cloud migrations have one genuine advantage over on premises moves: both ends are already cloud native, with automation, snapshots and elastic capacity on tap. Used well, that makes the mechanics smoother. For the full journey, start from the complete guide to Oracle Cloud migration.