Migrating Legacy Applications to the Cloud: A How To Guide

Posted on by Kelly Goolsby | Updated:
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Is your organization migrating legacy applications to a cloud platform like Microsoft Azure, AWS (Amazon Web Services), or VMware?

As today’s businesses seek ways to be more efficient, it's becoming clear that legacy application migration is one of the best ways to do so. Older applications and integrations can improve performance and security alike when moved to the cloud. According to industry analysis, more than 50% of organizations have already adopted a cloud-only strategy. This acceleration of digital transformation has major implications for legacy software applications. 

Thankfully, for many companies, migrating legacy apps to the cloud right away may now be unnecessary. Moving to the cloud is the short-term solution for added security and performance. It opens the ability to refactor or modify in a newer, more robust, and resilient environment.

If your organization counts legacy applications as critical to your workflows and business initiatives, then it is imperative that you plan for the future.

Ask yourself: 

  • How do you get the most out of prior investments? 
  • What are the best ways to keep applications secure? 
  • By what means can you optimize and recognize the performance benefits of the cloud without leaving behind critical applications?

In this post, we will dive deep into cloud migration for legacy systems and explore the paths available to you.

A Short History of the Cloud - VMware, AWS, and Azure

Data centers and cloud computing have been around for a long time. VMware introduced VMware vSphere back in 2006. Amazon Web Services (AWS) was founded as an Infrastructure-as-a-Service (IaaS) provider in 2006. Microsoft Azure was first released as a public IaaS provider in 2010.

VMware is the oldest of these three “big name” infrastructure providers.

In fact, VMware began releasing cloud-ready versions of its software two years before AWS. The company released a cloud-ready version of vSphere back in 2009, supporting AWS APIs to provision and manage capacity across local, private data centers and public clouds like Amazon EC2. 

VMware was ahead of the pack with a clear vision for how their software and virtualization could work across multiple clouds. 

Comparing Redevelopment Time With Azure or AWS 

As more companies deploy their next-gen apps to the cloud, they are left wondering how long it will take to modernize their legacy applications or whether they should start from scratch and build a new app completely from the ground up. 

Should they:

  1. Rewrite the app entirely?
  2. Explore a legacy to cloud migration?

These two options often come down to what best fits each business. Modernizing applications can be faster and require fewer resources. On the other hand, one challenge with moving applications to the cloud is ensuring that all critical data is transferred smoothly to the new system.

At the same time, it is important to consider all that goes into modernizing an application by building it from the first line of code:

  • Redevelop: Bear in mind the time required for redevelopment, including testing and deployment.
  • Refactor: Consider the projected time to modernize with current application development tools available in public cloud providers like Azure or AWS Cloud.
  • Rehost: Think about an alternate projected timeline to modernize the application inside a private cloud such as Private Cloud powered by VMware at Liquid Web.

Assess Legacy Software Architecture With VMware Private Cloud 

 Keep these questions in mind, when planning your legacy application migration to the cloud:

  • How well is your application designed? 
  • Is your application still relevant? 
  • Will there be any issues with latency, bandwidth, and security when moving your app to the cloud? 
  • If you are using or have built applications specific to one environment, will application performance scale properly across different data centers? 
  • What specific tools are available for monitoring and managing your app in this new environment?
  • Is the timing right for modernizing your applications? If not, does migrating now and refactoring later make sense?

With today's technology, you no longer have to decide between moving forward with new software or staying behind with outdated software that cannot keep up with business demands. In certain situations, updating legacy software may be counterproductive. 

For example, complex integrations or dependencies on other systems are good reasons to pause application updates. Additionally, there are some cases where an application is performing optimally already, and refactoring or rebuilding just doesn't make sense.

VMware allows businesses to revisit their current infrastructure and know they're making the right decision for all future needs by providing one platform that can be used across both old and new systems, including legacy apps built on web-scale infrastructures. Simplicity, security, and reliability are just a few reasons why companies choose VMware

With a software-defined data center (SDDC) platform, you'll be able to assess all your current and future needs in one place. This can help increase developer productivity and decrease time spent on debugging issues that could arise during the cloud migration process.

Why Don't More Businesses Migrate Legacy Applications?

Although migrating legacy applications to the cloud offers businesses several significant benefits, the process can be an uphill climb. Many company managers and executives are reluctant to migrate because of the sheer workload it involves. 

Some companies continue to straddle the fence and never pull the trigger on a migration because their current system is working – they adopt an if it ain’t broke, don’t fix it mentality. While there are some cases when sticking to legacy applications is the better option, many of these organizations seem “stuck in the mud” and afraid of the unknown of change.

Let’s take an in-depth look at the pros and cons of cloud migration. If you’re on the fence about migrating your legacy applications, this may be what launches your company’s IT assets into the future.

Different Ways To Migrate to the Cloud

Once you decide migrating legacy applications to the cloud is the best move for your business, it’s time to choose how. There are a few different methods, each with different features. We’ll walk you through them below so you can make the most intelligent decision for your organization. 


Refactoring is the process of rebuilding and fine-tuning legacy applications for performance on the cloud. You need to make sure refactoring is the right choice for your business before embarking on this path. The refactoring process requires investing a fair amount of time and resources and may also require significant coding changes. 

IT teams also need to remember to update any relationships with other apps. In most cases, legacy applications connect to several different apps across an organization’s IT infrastructure. If all of these integrations aren’t updated, your team may lose the functionality of key software applications.

While it takes some time, refactoring is ultimately the most sustainable method of cloud migration. However, the one downside is the cost. Refactoring requires an investment of time and money since it’s essentially an entire rebuild of a legacy application.

Since the process is so complex, it may require hiring an external migration specialist. But the cost will be worth it in the long run.

Lift and Shift

If your company is looking to migrate quickly, the lift and shift method may be for you. This method is typically the fastest and easiest way to migrate legacy applications to the cloud. 

Lift and shift doesn’t require new coding or architecting in the cloud environment because it uses an application’s original infrastructure. The only thing that changes is the hardware and the application’s new cloud environment. 

Using this method has one particular downside since legacy applications come from an on-premises environment. Because of this fact, legacy applications are comfortable processing a specific level of workload. 

The application's potential workload can change when you perform an on-premises-to-cloud migration. This creates issues when it comes to the management and scalability of the application itself. If you don’t foresee any issues with workload balancing and control, then lift and shift is a great way to get your cloud environment up and running quickly and easily.


For anyone looking to migrate legacy applications to the cloud, replatforming is a good compromise between the speed of lift and shift and the stability of refactoring. The process involves making small, easy changes to an application’s architecture to prepare it for use in the cloud. An example might be modifying the way a particular application communicates with databases so it can take advantage of serverless databases in the cloud.

During replatforming, the client side of the applications usually doesn’t change. This means companies can transition to the cloud without affecting their customer base. It’s a much faster process than refactoring and is typically the first part of modernizing a company’s legacy applications.

Issues may arise on the fly during the replatforming process. As long as your IT team is aware and adaptable, though, replatforming can be a valuable option. 

How To Help a Migration Go Smoothly 

Migrating legacy applications to the cloud is a big undertaking. Technicians may think they are taking all the right steps, but failure is still possible. Here are some cloud migration best practices to minimize your risk of loss, help your cloud migration go as smoothly as possible, and avoid any ISV migration challenges.

1. SWOT Analysis

You and your team should assess the pros and cons of moving to the cloud. You may find it’s not worth the upheaval of company processes, but you won’t know until you objectively look at how you’re currently using your legacy applications.

Using a SWOT analysis for this process is beneficial because it covers more than just the technical aspects of the migration. Overall costs, necessary employee training, compliance, and security measures are all considered. This bird’s eye view will help you strengthen your planning process and spot any loopholes your team needs to be wary of.

2. Evaluate the Environment

Before starting your migration, you must evaluate your current IT environment. Fortunately, there are tools to help with this process. Microsoft provides IT techs with its Microsoft Assessment and Planning (MAP) toolkit. This toolkit covers the following:

  • Capacity
  • Network architecture
  • Performance requirements
  • Infrastructure
  • Availability
  • Resilience requirements

Use this tool to review and document your current procedures in each area. You’ll also be able to leverage the MAP toolkit to uncover any new maintenance procedures you’ll need in your new cloud environment.

3. Choose Your Strategy

What’s most important to your team? Do you want to get the cloud up and running quickly, or is your focus more on stability? Maybe you need a migration method that’s more middle-of-the-road. Regardless, you need to assess your team’s individual needs and decide which one of the above methods is best. 

4. Test First

It’s a good idea to run a test or pilot migration before you begin the actual process. This allows you to test the migration in a safe simulation environment that closely resembles the actual conditions where your migration will take place. 

While running a pilot migration may take time, that’s really your only investment at this point. It’s a safe, low-risk environment for users to test the applications as they would use them in a real environment and work out any kinks or bugs. As long as time is not an issue, it’s a worthwhile investment to flesh out any problems prior to the live migration.

What Does VMware Do?

VMware's entire purpose is to allow you to run multiple virtual machines (VMs) on a single server or across multiple servers using virtualization. Since coming to market, VMware has optimized its stack for cloud infrastructure. VMware has always been about having lower infrastructure costs by bringing a better density of VMs per host. 

VMware naturally brought the same benefit when transitioning from physical servers to hypervisors running in a VMware-supported cloud.

Fingers type on a laptop where the legacy to cloud migration process is shown

What Is VMware Private Cloud?

VMware Private Cloud is a VMware-based cloud computing platform that enables customers to modernize their applications without re-architecting legacy software, saving time and money by avoiding costly rewrites of code. This service can be used with VMware vCloud Director and VMware Fusion to provide organizations and enterprises the ability to deliver on today's digital business expectations while maintaining legacy systems. VMware Private Cloud also provides a cost-effective alternative for application modernization compared to other cloud solutions such as Azure or AWS.

It is important to note that legacy code does need to be updated, rearchitected, or refactored at some point to gain the full benefits of the cloud. With VMware Private Cloud, organizations can move these applications to the cloud to start updating and modernizing the code without fear of data breaches or physical hardware failure. 

How Does VMware Support Legacy Applications without Refactoring?

VMware Private Cloud empowers IT to provide a platform for application modernization and expansion to the cloud while allowing businesses to plan better on modernizing legacy applications.

VMware Private Cloud supports application modernization by providing VMware-aware virtual machines. VMware-aware VMs make running applications and workloads in the cloud simple, even for complex deployments. Legacy applications and old code bases that might otherwise struggle in AWS or Azure can find a home in the cloud with VMware. And in that home, they can be updated responsibly and be set for growth in the long term.

How Does VMware Help with Legacy-to-Cloud Migration? 

It's important for IT to support digital transformation while maintaining legacy systems. VMware Private Cloud with Liquid Web can help VMware customers with migrating legacy applications to the cloud without having to re-architect or rewrite code for legacy applications.

VMware Private Cloud provides a cost-effective alternative for application modernization when compared to other cloud solutions such as Azure or AWS. The addition of VMware Private Cloud gives these organizations a new option for moving or expanding a wide range of applications, including their virtual desktop infrastructure (VDI) deployments, into the cloud. In addition, these teams can take advantage of other cloud management tools that help improve processes and operations.

VMware essentially serves as the glue that combines older applications with the cloud. While applications hosted on physical hardware will require a data migration, the path to the cloud is made easier with VMware. Most public cloud deployments have inflexible requirements for how code is developed, deployed, and run. VMware supports code that was built for different infrastructures - and at a different time.

It's important for IT to support digital transformation while maintaining legacy systems, and VMware Private Cloud with Liquid Web allows businesses to continue using legacy applications without refactoring them right away. Organizations can immediately leverage some benefits of the cloud while forming a modernization plan for when the time is right.

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About the Author

Kelly Goolsby

Kelly has worked in the hosting industry for nearly 16 years and loves seeing clients use new technologies to build businesses and solve problems. His roles in technology have included all facets of Sales and, more recently, Solution Architecture, Technical Sales, and Sales Training. Kelly really loves having a hand in developing new products and helping clients learn how to use them.

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