Legacy database migration is inevitable for most modern businesses.

At some point, businesses that use software, either third-party or proprietary, enter a phase when legacy database migration is inevitable. Just thinking about it may give CEOs and CTOs gray hair. Modern companies, especially big enterprises, continuously generate reams of data, and a large portion of this data is stored in obsolete systems.

So there is always a fear that some valuable information might get lost or corrupted during the transition.

The good news is that the process of moving legacy databases to new environments isn’t always as bumpy and risky as it may seem. The migration can be smooth and safe if everything is done correctly — with the right procedures and expertise.

This article explains what exactly legacy database migration involves and why it is worth the effort. We’ll also discuss some common challenges that you may face down the road and give you some tips on how to overcome them on our experience reengineering legacy software.

What is legacy database migration?

Legacy database migration is the process of moving data from an obsolete storage to an up-to-date environment.

Simply put, legacy database migration is the process of moving legacy data from an obsolete storage system to an up-to-date environment while keeping its value and dependencies intact. But let’s take a closer look:

  • Legacy data. The term “legacy data” means that information is historical or, in other words, was accumulated during the organization’s past activities. Besides being buried in old software, legacy data is often poorly structured and has out-of-date formats. However, none of these means that this data is useless; on the contrary, it’s vital for a business and, thus, worth storing.
  • Obsolete storage. Basically, this is a database environment that can no longer ensure the effective use of data. Why? Most often, it’s because this environment relies on technologies that are past their prime or third-party IT infrastructures that a vendor has ceased to support (for example, a software system based on MS-DOS).
  • An up-to-date environment. This environment represents an advanced modern system that meets the growing needs of today’s businesses (e.g., a cloud platform).

Depending on the business case, a legacy database migration process can also include data conversion or data integration. Data conversion happens when the original data is translated into a different format, while data integration means that the data from different sources is combined into a single database.

That said, many outdated database environments are still in use.

So the question is: what is the business value behind the legacy data migration?

Would it just be easier to keep storing data in legacy systems? The short answer is no. But let’s discuss this in more detail.

Why do you need a legacy database migration?

Moving legacy data to a new location brings many benefits.

Usually, the question of moving legacy data to a new location arises when an organization replaces old systems with up-to-date solutions or modernizes its current IT assets. Here are the benefits you can expect if you decide to migrate.

Cost optimization

Maintaining obsolete systems that store legacy data is both difficult and costly. A lot of resources and effort are required just to keep them running, not to mention scaling up or integrating with the rest of the company’s IT infrastructure. Why is that the case? The common reasons include:

  • Frequent failures. Software becomes more and more cumbersome and prone to crashes over time. Fixing it while trying to keep routine workflow uninterrupted requires the engagement of additional employees, which logically leads to additional expenses.
  • Shortage of professionals. When the technology is out-of-date and nobody uses it in modern solutions, finding a developer who knows how to work with it is hard. The lack of professionals results in intense competition in the employment market, which means higher rates and increased recruiting costs.
  • Restricted capabilities. Even if a legacy system is up and running, it’ll never offer the same capabilities as modern software. Some integrations won’t be possible, while the level of automation won’t be able to keep up with current standards. In other words, a business will be tied to high expenses with few opportunities to optimize them.

Summing up, migrating legacy data to a new environment is critical if you want to keep this data but don’t want to be burdened with high and unnecessary costs. Naturally, the transition of legacy data requires some initial investment. But it pays off since it allows for considerable cost optimization in the long run.

Data-driven decision-making

Another reason to migrate from a legacy database to a new database is an improved quality of data-driven decision-making. As mentioned, the data in obsolete systems is usually stored in out-of-date formats. Besides this, it’s often siloed, inconsistent, and overflowing with redundancies. Combine that with the restricted capabilities of an old database environment, and you’ll end up with large amounts of accumulated data that your business cannot use to the fullest.

Meanwhile, modern storage environments have a sophisticated underlying architecture that allows companies to eliminate a lot of the problems associated with legacy data. So once the migration is completed, an organization can use all of its data effectively for strategic purposes, including advanced analytics.

Why is it so important?

Data-driven businesses outperform their competitors in a variety of areas: product/service improvement, customer experience, increased revenue, and cost reduction. So, if you complete data migration from a legacy database and implement modern data analytics, you’ll be able to get a considerable competitive edge.

Enhanced data accessibility

Outdated systems were not designed to meet the current demand for all-around data accessibility. So, no wonder they cannot offer the level of data availability required to meet the needs of modern organizations.

For example, it’s not always possible to access a legacy database through different devices. And even if a user can do this, finding the piece of information needed for a specific task can be challenging and time-consuming. This might seem just a minor inconvenience, but this aspect can greatly affect business resilience, impairing the organization’s capability to survive in today’s unstable landscape.

One example is the COVID-19 pandemic. It caused a global shift to the work-from-home model. According to Mercer, 70% of surveyed US employers said that they plan to adopt hybrid work arrangements, while some companies like Twitter and Slack have already made this transition. Data accessibility is the foundation of remote working.

So without legacy data migration, these changes wouldn’t be possible for many companies.

Improved data quality

Some C-suite managers hesitate to migrate from a legacy database to a new database because of the fear that the data may become corrupted during the transition. No one wants to put at risk the accuracy of information that has been accumulated over a long time. But this concern has nothing to do with the way everything happens in practice. When legacy data migration is done correctly and by a team of professionals, you can actually improve the quality of your data, not impair it.

In general, data is considered of high quality if it’s accurate, consistent, complete, valid, unique, and timely. Legacy databases cannot fully ensure compliance with these criteria. As mentioned, the data stored in obsolete systems is often siloed and poorly structured. Duplication is also common, and the availability isn’t sufficient. If a company transfers the data to a modern environment, it can get rid of these issues and, as a result, achieve a higher level of data quality.

Limitless scaling

Today’s businesses tend to expand their digital presence and grow their IT assets over time. Meanwhile, one of the main problems with out-of-date databases is that they offer limited opportunities for scaling up. As a result, software that was once supposed to help a company reach its objectives complicates or even hinders its business development.

Data migration from a legacy database to a new environment solves this issue. For example, cloud-based infrastructures can easily adjust to the company’s current needs. You can scale the cloud capacity up (or down) as necessary to handle more (or fewer) tasks and users. Since the cloud doesn’t require heavy investments in hardware, it opens practically limitless opportunities for business growth.

Read also: Legacy Systems in Healthcare

3 Main challenges of legacy data migration

The process of legacy data migration involves many challenges.

Although legacy data migration brings many benefits, the process isn’t easy. To be successful, you should be aware of the pitfalls you can encounter once you kick off the transition. Here is a list we created based on our experience in similar projects.

Low quality of legacy data

If you decide to migrate from a legacy database to a new database, a low quality of legacy data will probably be the first issue you’ll have to deal with. Legacy data often doesn’t meet today’s quality standards. So, you’ll need to assess the state of the data stored in obsolete systems, study the relationships behind it, and decide if some improvements or changes must be made before the migration.

Lack of management commitment

That’s another aspect that holds back IT modernization initiatives, including those related to legacy database migration. For many C-level managers, the idea of moving large amounts of data from one location to another sounds intimidating. The popular misconception is that if a system still works, it’s better to leave everything as it is.

But if business decision-making is ruled by fear of the unknown, a company risks lagging behind its competitors. So, it’s crucial to get everyone on the same page before starting the legacy data migration project.

Lack of expertise

To complete a legacy database migration project successfully (i.e., without any data getting lost or corrupted), you need to have people with relevant expertise on board. Naturally, not every organization employs an in-house specialist who knows how to migrate legacy data. But that shouldn’t be a problem since you can always find a legacy database migration partner that will guide you through the entire process.

Now that you know what to expect, let’s talk about the key requirements for a data migration project and the steps you should take to meet them.

Key requirements for the legacy database migration

Before initiating legacy data migration, you need to meet a number of requirements.

Legacy data migration is a complex process, so you should prepare for it in advance. Here is a list of requirements you must consider before proceeding with the transfer.

  • Completing a data audit. This preliminary step is crucial since it’ll help you get rid of existing errors in the data and its dependencies. You’ll also be able to identify sets of data that your business no longer needs and delete them before the transition. So, you won’t need to waste resources on moving unused datasets during the migration.
  • Ensuring data security. Meeting this requirement is paramount if you want to avoid data leaks and cyber attacks when migrating to a new storage environment. You must use legacy database transfer tools that offer an adequate level of data protection. Also, make sure the team working on the migration project applies data security best practices.
  • Making realistic estimates. Data transfer cannot be carried out in a few hours by just copying data sets from one storage and pasting them into the new storage. Legacy database migration is a lengthy process that requires a lot of time, money, and effort. So before starting, put enough resources into thoughtful planning.
  • Establishing the process. It’s important to take care of all the administrative aspects of legacy data migration beforehand. Make sure that the team has all the necessary tools and understands what they’re doing and why.

Skipping any of these requirements may cause unexpected problems during the migration or errors in data after the transfer. The preparation stage will take some time, but it’s worth it.

Now let’s discuss how to migrate from a legacy database to a modern environment and what phases this process includes.

Legacy data migration process step-by-step

6 stages are common for most legacy data migration projects.

The process of legacy data migration can differ slightly depending on a number of factors: the team’s approach, the amount of data to be transferred, the timeline, etc. But the stages below are the common core for most data migration projects.

Step 1. Creating a migration strategy

Legacy database migration should be a separate project even if it’s part of a more global business initiative (e.g., the adoption of a new software solution). That’s why you need to create a strategy specifically for it before taking any practical steps. Here is a list of key things to include in this strategy:

  • Scope of your project. Basically, this is a high-level overview of what should be done, what systems will be covered, and what business processes will be affected.
  • Migration approach. You’ll either move data to a new location in one go or carry out the migration gradually. Everything depends on the specifics of your business case, timeline, and technical requirements.
  • Legacy database transfer tools. It’s also critical to decide what tools a development team will use and include them in the project documentation.

These are just basic elements of a data migration strategy. In general, you can include in this document any aspect that is important for your project.

Step 2. Making a data backup

Data backup ensures that you’ll be able to restore the original database if some mid-migration issues occur. Even if your team is professional and has several successful data transfer projects in its portfolio, skipping this stage may result in lost data. So it’s always better to be on the safe side.

Step 3. Preparing the target environment

Before moving legacy data to a new environment, you should prepare this environment for migration. The specific aspects of this process will depend on the type of storage you choose. But, in general, you have to make sure that a target system is up, running, and ready to receive your data.

Step 4. Testing the data migration

Once everything is set, you need to test all the migration steps with small amounts of legacy data. This will allow you to see if you haven’t missed anything and if the data transfer goes as it was supposed to. Also, you’ll be able to correct any mistakes or get rid of bottlenecks that were not evident before.

Step 5. Migrating the data

It is the core stage of the entire process. After successful testing, you can proceed with the migration of the remaining data. It’s a good idea to use one of the automated migration solutions available on the market. For example, AWS offers a set of migration services for businesses that want to transfer data to AWS cloud infrastructure.

If you move large amounts of data stored in a system that is essential for some business processes, you may need to suspend these processes during the transition period. But migration can also be carried out without workflow disruption.

You need to discuss all possible scenarios with your legacy database migration partner to choose the most optimal solution for your organization.

Step 6. Monitoring the system after the migration

After the legacy data migration is completed, you should continue monitoring the new environment to see if everything runs properly. This will allow you to detect and fix issues early on — before they become a systematic problem.


Moving legacy data to modern storage might be a hard decision for the company’s C-level managers. But this step is necessary if an organization wants to stay afloat and grow in today’s fast-changing environment. In addition, legacy database migration can bring a number of benefits, including cost reduction, better decision-making, improved data accessibility, and limitless scaling.

That said, migrating legacy data is a complex activity. To make it a success, a team working on the data transfer must possess relevant expertise. Acropolium legacy software modernization team has helped many businesses undergo IT modernization and move data to a new environment. Get in touch, and we’ll be happy to discuss your project.