Achieving high VM density in Kubernetes demands advanced memory management. This talk details our journey building the VM higher density solution for OpenShift Virtualization (KubeVirt).

With Kubernetes swap previously in Beta, we needed an immediate way to enable worker node swap. Enter wasp-agent: our custom project to mimic K8s swap externally. We will explore the technical hurdles of this approach, detailing our experiments with Linux cgroups, runtime hooks, and evictions.

As we trace the solution’s evolution from Dev Preview to GA, attendees will learn about memory overcommit mechanisms (FPR, KSM). Crucially, we'll detail our transition plan: deprecating wasp-agent to adopt the newly GA'ed native Kubernetes swap, highlighting the platform tunings required for maintainability and consistency.

Finally, we'll evaluate deployment strategies, comparing Operator-driven automation against manual methods, and the trade-offs of enabling swap at install-time vs on a running cluster.