What Is Cloud Migration? Definition and Guide

Cloud migration is the process of moving data, applications, or processes to a cloud computing environment, which uses internet-based storage and services.

More and more companies are moving operations to the cloud. But the cloud isn’t new—it was first conceptualized in the 1960s as a way for two people to use the same computer simultaneously. However, the modern cloud migration trend didn’t take off until the late 1990s and early 2000s and has since rapidly increased.

Cloud migrations enable you to transition from traditional on-premises infrastructure to contemporary cloud platforms that can better serve your organization’s and—crucially—your customers’ needs. Here’s what you need to know about moving your computing resources to the cloud.

What is cloud migration?

Cloud migration is the process of moving data, applications, or business processes to a cloud computing environment, which uses internet-based storage and computing services as opposed to hosting and managing data and applications locally within your physical infrastructure. You can move from an on-premises environment to public or private clouds or from one cloud environment to another (“cloud-to-cloud” migration). 

Legacy infrastructure, such as aging servers or unreliable firewall appliances, is often unreliable, inefficient, and unable to support a company’s growing data capacity. Cloud-hosted data can be accessed anywhere that has an internet connection, whereas legacy technology relies on having access to physical servers and data centers. Migrating to the cloud makes it easier to scale your business and manage it yourself (through self-service provision). You can also pay for only the amount of storage you use.

Not all applications or workloads are suitable for cloud storage. The flexibility, scalability, accessibility, reliability, and cost-effectiveness offered by cloud storage make it an ideal choice for public-facing apps with a global reach.

There are five cloud migration strategies you can choose from to move your applications to the cloud. Your chosen strategy depends on how many applications you wish to move to the cloud and how easily the application operates in the new environment.

1. Rehost (“lift and shift” migration)

When you rehost, you “lift and shift” your existing data and applications from local servers to cloud servers without making significant changes to the architecture. Think of rehosting as the same app but on a cloud server. This is the most straightforward migration strategy and is ideal for organizations less familiar with the cloud or where modifying your application’s code is challenging. 

2. Refactor 

Refactoring, or replatforming, uses existing code and frameworks to rearchitect your applications to align with cloud-native services and frameworks. You can refactor an application to improve performance, optimize functional needs, conform to enterprise standards, and adapt to security needs—all while maintaining some level of compatibility. 

3. Revise 

Revising involves partially rewriting or expanding the app’s code base, then deploying it by either rehosting or refactoring. It involves adjusting components to fit the cloud environment better and enabling applications to take full advantage of cloud services.

4. Rebuild

When rebuilding, you rewrite and rearchitect the application from scratch. The benefit of rebuilding your application is that you can make it cloud-native from the get-go, so it operates flawlessly in your cloud environment. Additionally, developers can incorporate modern features from their cloud provider in their new applications. However, this process is time and labor-intensive and should only be considered if your existing solution does not function properly in the cloud. 

5. Replace

In a replacement strategy, you migrate to a third-party, pre-built application provided by the vendor. This can benefit organizations if they know they need a cloud-native application but don’t have time to rebuild it themselves. It can also make it easier to manage the application, since you’re using one already built for you by your cloud provider. You only need to give them the data you want to use, and they’ll do the rest. 

Cloud migration process

1. Develop a business use case and migration strategy

2. Analyze your existing infrastructure to determine your needs

3. Choose your deployment model and cloud provider

4. Create a cloud migration plan

5. Execute and test the migration

6. Optimize your cloud infrastructure

While the migration process varies by company, it generally follows the same course of action. Here is a step-by-step cloud migration checklist to keep in mind before and during implementation. 

1. Develop a business use case and migration strategy

Every application, process, and workflow you plan to migrate to the cloud needs a business use case. Understand the value you can gain from moving your data, applications, and business processes to the cloud and establish goals to determine the success of the migration. 

2. Analyze your existing infrastructure to determine your needs

Before embarking on your migration project,audit your applications and workflows to decide specifically what you want to move to the cloud, how much data you need to move and how quickly, and how to migrate this data. Each application and workflow may require a different approach.

3. Choose your deployment model and cloud provider

Based on your requirements, choose a cloud deployment model: public cloud (offered by a third-party cloud provider); private cloud (the organization controls the cloud environment, meaning it isn’t shared); hybrid cloud (two or more types of cloud environments); or multi-cloud (two or more public cloud environments—for example, using Google Cloud and Microsoft Azure in the same environment). Then, select a cloud tool, such as Google Cloud, Microsoft Azure, or Amazon Web Services (AWS), that meets your requirements.

4. Create a cloud migration plan

Cloud migration planning includes details such as the priorities and sequence of workloads you plan to migrate, the timetable, the cloud platform and cloud migration strategy, roles for execution, and a stakeholder communication plan. You may want to create a document or deck outlinings the end-to-end plan, which stakeholders can reference through the process.

5. Execute and test the migration

Depending on your strategy, you might be rehosting, refactoring, revising, rebuilding, or replacing your application architecture. The next step is to test your workload and applications to ensure everything migrated into the new cloud environment works. If it doesn’t, you may need to rearchitect your application so it’s more compatible with the cloud environment.

6. Optimize your cloud infrastructure

Optimizing your new cloud infrastructure includes maintenance (software updates) and monitoring for real-time performance, usage, and stability data. It also includes assessing data security to ensure your new environment meets regulatory compliance laws like HIPAA and GDPR. 

Benefits of cloud migration

Cloud migrations allow businesses to transform digitally to innovate more quickly, efficiently, and effectively. There are several reasons why enterprises migrate to the cloud. 

1. Flexibility of access

The cloud allows employees or customers to access cloud services and data from anywhere ​​using any internet-connected device, enhancing productivity and enabling remote work. Cloud-based development environments and tools make it easier to meet changing consumer and market demands by quickly deploying new apps, services, and features. 

2. Security

The cloud offers a more secure environment than a legacy infrastructure because it operates on a “shared responsibility model,” where cloud providers take responsibility for securing the infrastructure while the customer is responsible for securing data and workloads. Cloud providers regularly update their security measures, offer built-in firewalls, encrypt the data, and provide redundancy (ultra-backed-up data). This makes it easier for organizations to comply with industry standards and government regulations such as GDPR and HIPAA. 

3. Scalability

A cloud environment can scale up or down as your needs change. It allows organizations to handle spikes in traffic or accommodate growth without investing in and managing more physical infrastructure.

4. Cost savings 

Because the cloud operates on a pay-as-you-go model, you usually only pay for what you need. Cloud providers also handle maintenance and upgrades, ​​eliminating the need for upfront capital investment in hardware and software so you can spend less on IT operations. This lowers your total cost of ownership (TCO)—the purchase price of an asset plus the operation costs. 

5. Performance 

The cloud improves performance, efficiency, and overall end-user experience. Cloud-hosted data travels further and faster, and users can access the same data no matter where in the world they are, in real time. Additionally, you’re less likely to experience disruptions or downtime than you do with on-premise servers.

Cloud migration challenges

While there are several benefits, migrating to the cloud can also present challenges and risks for your organization: 

• Cost. Cloud environments are dynamic and can rapidly change as new services are adopted and application usage grows. Costs can add up quickly if you’re not paying attention. Migration can also be costly if you’re transferring over large databases.

• Dealing with legacy applications. Only some applications or workloads make sense for the cloud. Decide which to keep and which to modify. Reformatting, rebuilding, or replacing applications can be time and labor-intensive.

• Integrating with current systems. If your cloud architecture isn’t compatible with your in-house IT infrastructure and operating systems, it can cause inconsistencies, misconfigurations, and interoperability problems. 

• Data migration. The biggest challenge in the migration process is carrying out the migration with minimal disruption and downtime. It can be time-consuming and may require high bandwidth connectivity. You risk impacting business operations if your data becomes inaccessible to users during the transfer. 

• Data security and compliance. While the cloud platforms provide robust security measures for the cloud environment through the shared responsibility model, you must configure all cloud services and applications correctly to ensure they have access controls and comply with industry regulations and standards.

• Training staff and managing third-party services. Managing apps in the cloud often requires a shift in IT skill sets and workflows. Train your staff appropriately to ensure the cloud environment's stability and security. 

• Service availability and reliability. Because you rely on a third-party cloud provider, your services and applications depend on how their network operates. Downtime or outages on their end can directly impact your business operations and cause disruptions and lost productivity. 

Tips for a successful migration

Migrating to the cloud is significant for any organization that requires proper planning, strategy, and stakeholder buy-in. From security to cloud provider selection, a lot can go wrong during the migration process. Follow these tips for successful cloud migration:

• Choose a vendor-agnostic cloud provider. Avoid vendor lock-in—dependency on a specific vendor's products or services—by choosing a cloud provider that integrates with your existing systems and applications. 

• Plan. Develop a roadmap outlining your migration schedule, and determine how you plan to migrate data to the cloud and who is responsible.

• Test and validate the migration. Test each performance aspect before and after each element moves to the cloud, such as how it performs in the new environment, response time, security and access, and any failure conditions. 

• Continue to monitor and optimize the new cloud infrastructure. Monitor the environment for real-time data performance, usage, and stability changes.

• Prepare a security plan. Establish governance rules and structures, manage access, and monitor the cloud environment to avoid data breaches.

• Create a reverse cloud migration strategy. A cloud exit strategy is handy if you need to move data out of the cloud and return it to its original state on-premises or to a private cloud.

Cloud migration FAQ

How do I choose a cloud provider? 

To choose a cloud provider, assess your existing infrastructure to understand your specific needs for availability, support, security and compliance, and pricing to find the best fit. Amazon Web Services (AWS), the Google Cloud platform, VMware Cloud, and Microsoft Azure are some of the most common and popular cloud providers. 

Can cloud migration cause data loss?

There is a risk of data loss if you move large amounts of data and configure access controls across domains.After migrating data to the cloud environment, check for data integrity to ensure the data is intact and secure.

Is cloud migration expensive?

Cloud migration is less costly than legacy infrastructure because of its pay-as-you-go pricing model. However, you still need to estimate future cloud costs based on the amount of storage you expect to need, cloud resources, and specific performance and network requirements.

Is it necessary to hire a third-party cloud migration service?

Hiring a third-party cloud migration service is unnecessary if your IT team can handle the migration. However, outsourcing may be worth considering if you have a small IT team.

Which cloud model fits best?

The suitable cloud model depends on the nature of your workload and the type of data and applications you’re looking to migrate. Public cloud provides scalability through a pay-per-usage model. Alternatively, private cloud offers extra control and security. If neither works, you may opt for a hybrid or multi-cloud environment.