If you’ve been working with VMware for a decade, you already know this: legacy systems can be like old furniture. Sure, they’re familiar, and maybe even comfortable. But as the world shifts towards Kubernetes and cloud-native infrastructure, it’s time to consider how much longer you can sit on that squeaky chair before it finally gives out.

Transitioning to Kubernetes doesn’t have to mean throwing out everything at once. In fact, like all good infrastructure projects, it’s about understanding where you are, defining where you want to go, and managing the steps in between.

The Roadmap to Modernization

Modernization comes with choices. You can take the "failure is not an option" moonshot approach with a full cloud-native overhaul, or ease into it through a phased approach. This flexibility helps reduce risk while adapting to evolving business requirements. 

There are two key takeaways: modernizing is not a one-size-fits-all scenario. 

• First: consider your options, from upgrading legacy apps to fully exiting VMware, while factoring in your appetite for risk and change. 
• Second: the steps below are not a linear sequence or checklist. Different parts of your application and workload estate may fit some of these transitions and not others. (Spoiler: a big part of what we do at CloudGeometry is to help figure this out). 

The biggest risk at this stage is underestimating complexity. Deciding to modernize without fully scoping the resources, timelines, and organizational readiness can result in incomplete transitions or half-baked solutions that leave teams frustrated and applications underperforming. A clear understanding of both costs and benefits is crucial before embarking on any migration strategy.

1. Starting with Your Legacy App

Most VMware environments are still home to applications running on vSphere or even physical servers. These legacy apps continue to deliver critical business value, but the walls are closing in. They need more agility, better integration, and faster deployment options. The challenge? How to modernize without disrupting the delicate balance these systems hold within the enterprise.

Risk: Legacy applications often have undocumented dependencies and complex integrations with other systems. Moving too quickly without a complete audit of these dependencies can lead to outages or degraded performance post-migration. Take the time to assess how interconnected these apps are with other business-critical systems to avoid unexpected downtime or broken workflows. Bear in mind, not every function in your application merits a rewrite.

2. The Classic ‘Lift and Shift’

Here’s where most teams start. The “Lift and Shift” approach is all about getting your app from VMware into the cloud – typically AWS EC2. Think of it like moving into a new home but bringing all your old furniture. It works, but the fit might not be perfect, and there’s always a risk that something will break during the move. The real issue here? Configuration dependencies. Ignore them, and your ‘shifted’ app might not behave so well in its new environment

Risk: In a lift-and-shift strategy, misconfigured infrastructure settings can lead to performance degradation or unexpected costs. On-premise VMs are often tightly tuned to the hardware they’re running on. Moving to cloud-based infrastructure without adjusting for the performance characteristics of the cloud environment can lead to inefficiencies or service interruptions. Ensure you tune your cloud setup post-migration to avoid higher operational costs and poor performance.

3. Migrating Databases: The Heart of the Matter

Your database is often the beating heart of any legacy application. This stage focuses on ensuring your data infrastructure moves in tandem with your application. Whether migrating to Amazon RDS or a managed PostgreSQL instance, configuration management is still the name of the game. Get this right, and your application’s core services will continue to hum along.

Risk: Databases are sensitive to latency and downtime during migration. Improper planning for the migration process, especially for mission-critical data, can result in significant data loss or corruption. Always ensure you have robust backup mechanisms in place and plan for data reconciliation in case of discrepancies during migration. Testing migrations in a sandbox environment can help you avoid nasty surprises.

4. Moving to Containers: Think Docker

For those ready to ditch the legacy VM structure, the next logical step is containers. By lifting the app into Docker or another containerized environment, you start shedding the need for VMware VMs entirely. The result? Your app becomes easier to manage and is one step closer to Kubernetes. And while you’re not cloud-native yet, this move lays the foundation.

Risk: Not all applications are ready for containerization. Containerizing a legacy app without fully understanding its dependencies or limitations could result in operational issues or system crashes. Test your containerized apps thoroughly before migrating them to production, and ensure that any stateful components are correctly managed in the containerized environment to avoid data integrity issues.

5. Virtual Machines in Kubernetes: KubeVirt to the Rescue

Not every application can make the leap to containers. Here’s where Kubernetes shows its flexibility. KubeVirt allows you to run VMs within a Kubernetes pod, giving you the power of Kubernetes' orchestration without needing to fully re-architect your legacy app. Think of it like slipping your old furniture into a modular setup – you get the best of both worlds.

Risk: Running VMs inside Kubernetes adds a layer of complexity. It requires careful tuning of resource allocations to ensure VMs perform well inside Kubernetes pods. Over-allocating or under-allocating resources can lead to performance degradation or wasted resources. Monitoring the resource utilization of VMs within Kubernetes and tuning Kubernetes’ scheduling policies is key to avoiding bottlenecks or runaway costs.

6. Lift to Kubernetes

If your application can be containerized, then moving to Kubernetes is the next step. By leveraging Kubernetes’ StatefulSets, you can manage stateful applications with greater ease, scale more effectively, and enjoy the reliability of modern orchestration tools. At this stage, you’ve let Kubernetes handle the heavy lifting.

Risk: Stateful applications in Kubernetes need special handling. Migrating a stateful app without properly configuring StatefulSets or persistent volumes can lead to data loss or corruption. Make sure you understand how your app manages state and implement appropriate strategies for data persistence and replication within Kubernetes to avoid service disruption.

7. Containers in Kubernetes: Simplified Cloud-Native

Here’s where things get interesting. Breaking your application into multiple containers, all managed by Kubernetes, starts to shift the architecture toward cloud-native patterns. You don’t have to refactor the whole thing (yet), but this setup starts behaving in ways that mimic full cloud-native applications.

Risk: Fragmenting your application into containers without fully thinking through the communication and orchestration between them can introduce latency and complexity. Containerized services need to be well-defined and modular, and communication between them should be optimized using appropriate networking and service discovery tools to avoid performance bottlenecks.

8. Fully Cloud-Native: The Final Frontier

Reaching full cloud-native nirvana means refactoring some or even all of your application into microservices. Now, Kubernetes takes the reins on scaling, security, and configuration management. This is where your application not only survives but thrives in the modern cloud landscape. You’ve arrived.

Risk: A full microservices architecture introduces its own set of complexities, especially around observability, security, and service coordination. Without adequate tooling in place (like service meshes or comprehensive logging systems), managing a fleet of microservices can become a nightmare. Invest in the right DevOps and monitoring tools to maintain visibility and control over your microservices architecture.

In a world where cloud infrastructure continues to move faster than tickets to the next Taylor Swift concert, a deliberate, staged approach to modernization allows your organization to maintain agility while reducing the risks inherent in a major transformation. Moving from VMware to Kubernetes might feel daunting, but done right, it’s a journey worth taking – one step at a time.

We recently hosted a full webinar focusing on taking an even deeper dive into the power of Kubernetes