The uncertainty surrounding VMware's future after Broadcom's acquisition has led many organizations to reconsider their reliance on VMware solutions. For some, this moment presents an opportunity to reduce costs, modernize infrastructure, and enhance flexibility. But while the potential benefits are appealing, the associated risks are often underestimated.

Across the industry, one pattern stands out: about 80 percent of migration success relies on careful planning. Without proper planning, even the most advanced tools and skilled technical teams may fall short. Here are five critical mistakes that can hinder a VMware migration and how to avoid them.

1. Lack of Full Dependency Visibility

One of the most common mistakes in migration projects is overestimating how well the environment is understood. Most organizations only have partial insight into their application dependencies.

Applications are rarely self-contained; they rely on a complex network of interconnected servers, databases, storage devices, network configurations, and sometimes legacy systems that have been operating quietly for years. Missing just one critical dependency can lead to cascading failures, prolonged downtime, data corruption, or decreased performance.

Effective planning requires a clear and accurate overview of all dependencies across on-premises, cloud, and hybrid environments. This is where application dependency mapping (ADM) solutions become crucial. By automatically identifying and visualizing the relationships between components, teams can uncover hidden connections, assess risks, and establish an effective migration sequence. Faddom is an example of an ADM solution that is commonly used in VMware migrations.

2. Underestimating Hidden Costs

Many organizations pursue alternatives to VMware with the goal of achieving cost savings, often focusing on reductions in licensing, support, or hardware expenses. However, indirect costs are frequently overlooked, and these can quickly undermine the expected financial benefits.

Examples of hidden costs include extended downtime, emergency consulting fees, additional staff hours for troubleshooting, and performance slowdowns that can impact business operations. Due to migration needs, unplanned hardware or software investments may also be required.

To avoid surprises, teams should conduct thorough budget planning that goes beyond surface-level considerations. This includes modeling both direct and indirect costs and performing realistic risk assessments. For instance, what is the financial impact of a one-hour outage? How much will it cost to bring in specialized support if issues arise? Gaining a comprehensive understanding of potential expenses helps prevent teams from underestimating the total migration costs.

3. Application Compatibility and Portability Issues

Enterprise applications are often closely integrated with VMware environments and typically depend on specific VMware features, storage architectures, network configurations, or performance optimizations that may not be available on a new platform.

When transitioning to alternative hypervisors or cloud providers, compatibility and portability challenges often arise. Teams may face mismatches in APIs, unsupported features, performance variations, or failures in third-party integrations. These issues can disrupt service quality and may require costly refactoring.

The best approach to mitigate these risks is to conduct thorough pre-migration testing. This process goes beyond merely verifying whether a virtual machine starts. It includes performing functional and performance tests, validating integrations, simulating production workloads, and stress-testing under realistic conditions. This comprehensive testing provides teams with critical information needed to adjust configurations or re-engineer applications before the migration deadline.

4. Security Risks During Transition

Migration periods often expose organizations to increased security risks.

As systems are moved, security teams encounter new challenges: existing security controls may not transfer effectively to the new platform, hardcoded configurations might fail, and new components could create gaps in monitoring or access control. Additionally, migration activities may involve temporary access permissions, relaxed firewalls, or direct database access, all of which raise vulnerability levels.

One common mistake is to treat security as an afterthought or to assume that the default settings of the destination environment will provide adequate protection. This oversight can leave organizations vulnerable during a critical transition.

To mitigate these risks, security assessments and architecture reviews should be integrated into the migration plan from the outset. Security specialists must be part of the core migration team and be responsible for validating encryption, access management, monitoring, and compliance at every stage of the process.

5. Lack of Thorough Testing

Testing is often viewed as the final step before going live, and when under tight deadlines, it is frequently the first task to be shortened or eliminated. However, insufficient testing is one of the most common reasons why migrations fail or underperform.

Without validating application behavior, data accuracy, performance, and user workflows, issues will likely emerge only after the migration is complete. At that point, fixing these problems becomes more difficult, expensive, and disruptive.

Effective migrations should include multiple layers of testing, such as

• Pre-migration baseline assessments
• Pilot migrations in sandbox environments
• User acceptance testing
• Performance and scalability checks
• Failback and rollback exercises

By prioritizing testing, teams can identify and resolve issues early, ensuring that the post-migration environment meets or exceeds expectations.

The Takeaway: Planning Drives Success

The technical risks associated with moving away from VMware are very real and stem from the complexities of modern IT environments. While the potential benefits of migration can be significant, they can only be realized when approached with a disciplined and well-structured plan.

The most critical factor in predicting success is the effectiveness of the planning process. This involves mapping out dependencies, modeling costs, ensuring compatibility, enhancing security, and conducting thorough testing. When these elements come together, organizations can position themselves to reap the rewards of migration while avoiding common pitfalls.

In the end, success is not solely dependent on tools or technology; it is fundamentally rooted in careful planning.

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ABOUT THE AUTHOR

Ofer Regev, CTO and Head of Network Operations at Faddom

Ofer has 18 years experience in the IT industry. He currently serves as CTO and head of network operations for Faddom (formerly VNT), a startup that raised $12 million to help companies map IT infrastructure wherever it lives. Faddom is used to map and monitor over 1 million application instances at organizations like Coca-Cola, NetApp, and UCLA. He previously served in the IDF's elite computing and information services unit, Mamram.