What is Cloud Migration?

Here's a 360-degree overview of migrating to the cloud, including the benefits, types of cloud deployments, migration strategies, and more.

Here’s a 360-degree overview of migrating to the cloud, including the benefits, types of cloud deployments, migration strategies, and more.

Cloud migration is the process of moving an organization’s physical and virtual workloads, data, applications, and other IT resources into a cloud computing environment. Moving to the cloud means moving from legacy, on-premises infrastructure to a data center infrastructure that is (most commonly, but not always) hosted by a third-party service provider and accessed via the internet. Major cloud providers include IBM, Amazon AWS, Microsoft Azure, and Google Cloud Platform.

Today, cloud migration is transforming the way businesses operate in a significant way. From mitigating downtime to offering real-time disaster recovery services, today’s enterprises embrace cloud adoption to meet their business needs.

In fact, research shows that upwards of 50% of corporate data is stored in the cloud, and 94% of enterprises use some form of cloud to run their day-to-day operations. This all points to the fact that today’s enterprise businesses are actively adopting a cloud migration strategy to capitalize on the rich transformational benefits that the cloud provides.

Benefits of Cloud Migration

Today’s modern cloud environments provide incredible value to organizations independent of size and industry, from automation to workload optimization.

Scalability and Flexibility

One of the most significant advantages of cloud computing is scaling to meet market demands seamlessly. For instance, seasonal fluctuations in demand no longer required overprovisioning infrastructure. Just spin up what you need and quickly shut it all back down when demand subsides.

Optimizing Innovation

For organizations that invest heavily in DevOps, the ability to scale up and down test & dev workloads seamlessly and on the fly is a boon. Rather than partitioning dedicated computing resources on-premises, these elastic cloud workloads can scale infinitely and are only charged based on usage.

Cost Reduction

Physical infrastructure requires maintenance and in-house staff. In addition, it can be difficult to predict growth and do capacity planning, leading to over-purchase and overprovisioning of physical hardware. Moving to the public cloud means paying only for resources used since today’s public cloud pricing is structured in a “pay-as-you-go” model. Finally, a shift from CapEx to OpEx (i.e., paying for infrastructure on a monthly operational basis rather than investing heavy capital upfront) has become attractive to most businesses.


Though it seems counterintuitive to some enterprises, moving to a public cloud environment is more secure than in-house infrastructure. The top cloud providers constantly upgrade their infrastructure and adhere to all regulatory requirements designed to keep data safe from breaches. According to Gartner, a whopping 99% of cloud security failures will be the customer’s fault.

Types of Cloud Deployments

There are four types of cloud to look at when considering your migration strategy.

1. Private Cloud

Private cloud is a type of cloud environment architected to provide an exclusive cloud environment to a single company. Traditionally, private cloud architectures run within a dedicated physical environment owned by the company, protected behind the company’s networking and firewall configurations.

However, today, many private cloud environments run in a segmented public cloud environment. Here, cloud providers offer isolated private cloud environments that are dedicated to a given company.

2. Public Cloud

Public cloud is a cloud architecture model where a third-party cloud service provider offers cloud-native resources, services, and infrastructure.

Here, the underlying cloud computing infrastructure is shared among clients; however, this cloud infrastructure is logically partitioned so that clients are unaware of one another. And by design, clients do not have access to one another’s cloud resources.

3. Hybrid Cloud

Hybrid cloud is a cloud architecture that spans between an on-premises environment and the cloud. Here, a company may run critical production workloads in their on-premises IT infrastructure while running less critical test & dev machines in the public cloud.

This can offer a flexible, scalable, and cost-optimized solution for development while maintaining critical infrastructure on-premises.

4. Multi-Cloud

Multi-cloud denotes a cloud architecture design that spans between multiple clouds. For instance, organizations that adopt a multi-cloud approach may run part of their production environment in a public cloud environment such as AWS while running another part of their cloud environment in IBM. Organizations often use this design to enhance redundancy and resiliency.

Cloud Migration Strategies: The 5 R’s

There are several types of cloud migration strategies, each of which offers unique benefits to an organization based on its business requirements. Known as Gartner’s “5 R’s”: rehost, refactor, revise, rebuild, and replace, today’s organizations have access to an existing cloud migration strategy playbook that will help streamline the process.

1. Rehost

Rehosting, also known as “lift and shift” – is a relatively straightforward cloud migration strategy where organizations simply migrate on-premises workloads into a cloud infrastructure as-is.

Benefits: Rehosting is an excellent option for organizations that are looking for a quick and easy cloud migration process. By simply moving applications to the cloud “as-is,” organizations avoid the overhead of rearchitecting their on-premises environment to move more seamlessly into the cloud.

Considerations: This methodology is known for speed. When opting for a quick lift and shift, organizations may overlook security vulnerabilities and gaps in application efficiencies. Organizations must dedicate resources to performing security assessments and application validation when leveraging the lift and shift method.

2. Re-platform

Re-platforming is known as lift-and-optimize. Here, organizations will migrate critical workloads into the cloud, much like rehosting. However, in this model, the organization will also upgrade aspects of the cloud solution stack such as workload APIs or middleware upgrades to build more optimized, efficient cloud workloads.

Benefits: The re-platforming approach offers all of the efficiency benefits of the traditional lift and shift model, with the addition of some rearchitecting to ensure architecture security parameters are met, leading to a more resilient cloud environment built for longevity.

Considerations: Refactor often leads to framework lock-in. By altering the existing code of on-premises legacy systems to make them more efficient, organizations can unintentionally lock their existing application into the new cloud environment, making it challenging to migrate to other environments down the road.

3. Re-factor / Rearchitecting

Refactoring or rearchitecting offers an effective strategy for organizations with customized purpose-built on-premises applications that they want to migrate into the cloud. Here, organizations are tasked to completely re-engineer these customized applications to run seamlessly in the cloud. Often, this refactoring approach means a complete teardown and rebuild in their choice cloud environment.

Benefits: The benefit of refactoring is that organizations can continue to utilize customized applications that support critical business operations while capitalizing on efficiency, minimized cloud latency, and scalability.

Considerations: This process can require immense person-hours from in-house engineers familiar with the purpose-built customized application. This means that organizations are often required to divert resources from critical business processes to the refactoring process.

4. Repurchase / Replace

Re-purchasing or replacing is a cloud migration strategy where organizations scale down on-premises applications and services and purchase net new services in the cloud. Often, organizations employ this cloud migration strategy when outdated on-premises legacy infrastructure no longer meets business requirements requiring a migration to a more advanced cloud-native replacement.

Benefits: The repurchasing method can save organizations time, money, and resources by avoiding more resource-intensive migration strategies. Here, organizations can start fresh with cloud-native services that are streamlined, secure, and optimized to meet their business needs.

Considerations: The repurchasing approach does put an organization at risk of losing critical applications and historical data as they spin down on-premises applications and spin up net new applications in the cloud. Healthy data transfer practices can mitigate this into their choice cloud application.

5. Retain

Retaining is the right strategy for organizations who decide some critical machines may be better suited to remain on-premises. Here, organizations enter a hybrid-cloud model where some of their production workloads remain on-premises while some span into the cloud provider of their choice. This can be an excellent fit for organizations with some custom-built legacy applications that are easier to manage on-premises rather than migrating into the cloud.

Benefits: One of the primary advantages of adopting a hybrid-cloud model is that it builds in flexibility. The hybrid-cloud architectures allow organizations to pick and choose which workloads make sense to migrate into the cloud and which workloads should remain on-premises. Now, organizations do not have to over-commit resources to refactor or rearchitect legacy applications. They can simply leave these machines on-premises.

Considerations: Hybrid-cloud requires organizations to maintain some physical infrastructure which may be a deal-breaker for organizations that are looking to manage a cloud-first architecture. Consider the overhead, maintenance, and physical costs of managing on-premises machines to understand the cost-benefit of keeping these machines local versus rearchitecting and porting these workloads into the cloud.

Next Steps in Your Cloud Migration

As you consider a cloud migration, there are many ways to go. You may find that starting small with a migration of email services from an on-premises deployment of Microsoft Exchange to cloud-native services like Office 365 is an effective start to a larger cloud migration strategy. And it may make sense to lay out a full cloud migration roadmap. There are many options and considerations.

Eliassen Group is dedicated to helping organizations around the world develop and implement cloud strategies. Whether it’s supporting the early stages of a cloud migration process, or enabling an end-to-end purpose-built cloud migration strategy, Eliassen Group offers top-tier tailored cloud consulting services purpose-built to help you meet your unique business needs.