Rob Pankow 
Unified storage for containers and virtual machines on OpenShift becomes important when the platform is no longer just a container runtime. Once OpenShift also carries OpenShift Virtualization, KubeVirt, databases, and stateful platform services, storage cannot be treated as two separate operating models.
The goal is not to pretend that VMs and containers have identical storage behavior. VM disks, application PVCs, image imports, snapshots, and clones all create different pressure. The goal is to give platform teams one Kubernetes-native control model for provisioning, policy, performance, and protection.
Why Unified Storage Matters on OpenShift
The VMware-to-OpenShift journey often starts with a simple question: how do we keep VM workloads running while newer services move to containers? The storage answer decides whether that migration feels like a platform modernization or like another infrastructure split.
If containers use one storage path and VMs use another, platform teams inherit two provisioning models, two troubleshooting paths, and two performance baselines. That may work briefly during transition, but it becomes expensive when the OpenShift environment is expected to run production workloads long term.
Unified storage works best when it supports both VM disks and container PVCs through the same CSI-aligned operations while still respecting workload differences.
| Storage choice | What it solves | Where it creates risk |
|---|---|---|
| Separate VM and container storage | Fast migration if teams keep old assumptions | Two operating models and inconsistent day-2 behavior |
| Local-only storage | Simple first deployment for some workloads | Weak fit for mobility, failover, and mixed production estates |
| Generic PVC storage | One Kubernetes interface | May not provide predictable VM disk behavior |
| Unified block storage | One policy model for VMs and containers | Requires careful topology and performance design |
Architecture Pattern for Mixed VM and Container Estates
For mixed estates, the cleanest pattern is a block-first storage layer that presents Kubernetes-native volumes through CSI and supports VM-oriented behavior such as snapshots, clones, predictable latency, and migration readiness.
At a high level, the design looks like this:
This does not remove the need for workload-specific policy. A database StatefulSet and a KubeVirt VM should not automatically receive the same class, QoS envelope, or recovery policy. But they should be operated through the same platform vocabulary: StorageClass, PVCs, snapshots, placement rules, telemetry, and support runbooks.
Operational Guardrails
Platform teams should start with a small set of storage classes. A practical set might include a high-performance class for latency-sensitive databases and VM disks, a balanced production class for most stateful services, and a best-effort class for test or non-critical workloads.
The important guardrail is that VM carryover does not become a loophole around platform standards. VM disks should still have clear topology rules, performance expectations, snapshot policies, and recovery testing. Container workloads should receive the same operational discipline instead of being treated as automatically easier.
Planning to run containers and VMs on the same OpenShift platform? Talk to simplyblock about a unified storage model that covers VM disks, StatefulSets, and private-cloud day-2 operations. Talk to a storage architect
How Simplyblock Fits
Simplyblock fits this pattern as a Kubernetes-native block storage layer for OpenShift environments that need one storage foundation across VMs and containers. It supports the OpenShift modernization story without forcing teams to split VM storage and application storage into disconnected products.
For VMware-exit teams, this is especially useful. VM workloads can move into an OpenShift-led operating model while stateful application teams get the same underlying storage direction. The result is a cleaner path toward OpenShift HCI storage, KubeVirt storage, and broader VMware migration to OpenShift and Kubernetes.
The practical evaluation question is simple: can the storage layer support both VM-style disk behavior and Kubernetes-native day-2 operations without creating a second platform to run?
Questions and Answers
What is unified storage for containers and virtual machines on OpenShift?
It is a storage design where container PVCs and VM disks are operated through a shared Kubernetes-native storage model, usually with CSI, StorageClass policy, snapshots, and common observability.
Why does OpenShift Virtualization change the storage discussion?
OpenShift Virtualization brings VM disk behavior into the OpenShift platform. That means storage must support VM-style latency, snapshots, migration, and recovery in addition to ordinary container storage.
Should VMs and containers use the exact same StorageClass?
Not always. They can share the same storage foundation, but platform teams should still use different classes or policies when performance, recovery, or mobility requirements differ.
How does unified storage help VMware-exit projects?
It reduces the chance that VM carryover becomes a separate storage silo. That gives teams a cleaner path from VMware-era operations into an OpenShift-led platform model.
Where does simplyblock fit in unified OpenShift storage?
Simplyblock provides a Kubernetes-native block storage layer for OpenShift teams that want one storage foundation across VM disks, stateful containers, and private-cloud modernization programs.
