Many companies are currently discussing the migration of individual applications or an entire IT environment to leading hyperscaler cloud platforms. But only a few know the strategies available and even fewer choose the right one, while most end up dealing with unnecessary hassle and disruption to their business operations.
Our goal here is to guide you away from such pitfalls by introducing you to the different migration strategies. By the end of this article, you will understand what a cloud migration is, what types there are and how to select the strategy best suited for your needs.
So first things first: What is a cloud migration?
A cloud migration can be understood as a physical move of data, applications, and IT processes to the cloud, from a data centre which you either operate yourself or have rented from an external provider. A move from a private or hybrid cloud model to the public cloud is also referred to as a cloud migration.
Just like moving to a new house, where boxes need to be packed, labelled and stacked, a migration to the cloud requires some preparation and planning. First and foremost, this includes selecting the environment or applications that you plan to move to the cloud. Additionally, choosing the right type of migration is critical.
Seven strategies for cloud migration
Building on the five strategies identified by Gartner in his study back in 2010, the leading hyperscalers in the public cloud sector describe seven common migration strategies for moving data and applications to the cloud:
#1: Refactor or Rearchitect
In this migration strategy, you move an application or change the architecture by leveraging the cloud-native value-adds of the new environment to improve agility, performance and scalability. A simple example of this is moving an operating system or database to the cloud. For example, in AWS cloud-speak, this could involve migrating your on-premises Oracle database to the Amazon Aurora PostgreSQL-compatible service.
#2: Replatform or also "Lift & Reshape"
The "Lift & Reshape" strategy refers to the migration of an application to the cloud, which also involves optimisation. The aim here is to use the advantages of the newly gained cloud functions for the application itself.
#3: Repurchase or "Drop & Shop"
As the name of the migration strategy suggests, this involves the repurchase of a product, usually switching from a traditional licence to a Software-as-a-Service (SaaS) model. For example, if you migrate your local CRM system to a provider such as Salesforce, HubSpot or others, you will be buying a new product, but one that is operated for you on-demand in the cloud.
#4: Rehosting or "Lift & Shift"
"Lift & Shift" represents one of the most well-known migration models, largely due to its quick implementation time. In rehosting, your application is moved to the cloud without any changes. You take advantage of the cloud environment, such as cost transparency or scalability, but do not perform any optimisations on the application itself.
A concrete example in the AWS world is migrating your on-premises Oracle database to Oracle on an EC2 instance in the AWS cloud.
#5: Relocate ("Lift & Shift at the hypervisor level")
Relocate pattern migration describes moving infrastructure to the cloud without buying new hardware, rewriting applications, or changing your existing operations. So far so good.
However, one important detail is that it can only be deployed via VMware Cloud from Amazon Web Services (AWS), which only supports virtual machine (VM) compatibility and workload portability between your on-premises environment and AWS. Sounds complicated, but remember: it's all like "Lift & Shift", just exclusively for VMware applications.An example would be migrating your hypervisor hosting your Oracle database, to VMware Cloud on AWS.
#6: Retain
In a “Retain Migration”, you keep your applications in their current environment—be it an existing data centre or an already-functioning cloud setup. This strategy is often chosen for applications that require extensive refactoring, and thus planned to be moved at a later date. Legacy applications you wish to keep operational without migrating fall under this category as well.
#7: Retire
Last but not least, the “Retire” strategy, much like the “Retain” strategy, is also relatively passive. In this approach, you decommission or remove applications that are no longer necessary within your current environment.
Spoiled for choice: Choosing the right strategy for your cloud migration
Now, let’s delve into how to select the appropriate cloud migration strategy from the options available. Which approach will facilitate a smooth migration of your IT environment or applications to the cloud?
Cloud migrations are a crucial part of any cloud strategy. That’s why hyperscalers have developed special programs to help both experts and customers explore their options and assess the benefits. These programs particularly focus on which environments and applications are most suitable for cloud migration, considering both operational efficiency and cost-effectiveness.
For example, Amazon Migration Evaluator
(formerly TSO Logic) helps you clarify and accelerate the decision-making process for your cloud migration. The first step is to collect relevant data from your IT history as well as from your current operations. Based on this data, the tool generates a personalised assessment for you, including a cost estimate as well as an analysis of the expected savings in various migration scenarios. The assessment will provide clear direction for specialists and customers to initiate migration planning and, furthermore, these results can also inform your management decisions.
In conclusion, a successful migration entails informed decision-making, in-depth analysis and meticulous preparation, i.e. the right strategy and planning. To achieve all that, having the right expert by your side is extremely important.