Individual Provider Block Storage vs. Longhorn

Buying Dependency or Building Resilience

Block storage is one of the invisible yet most critical layers of any cloud and Kubernetes architecture. Whether it’s AWS EBS, Azure Managed Disks, or similar provider-specific offerings: they work reliably—as long as you stay within the respective ecosystem. This assumption is rarely questioned.

With the increasing platformization of Kubernetes, block storage evolves from a detail to a strategic decision. Longhorn challenges the fundamental assumption that persistent storage must be tied to a single provider.

Provider Block Storage: Convenient, Stable—and Binding

Provider-specific block storage is designed for maximum convenience. Volumes can be provisioned with a click or via API, snapshots and backups are integrated, and performance profiles are clearly defined. This is attractive for traditional VM workloads or simple Kubernetes setups. Operations and availability seem “solved.”

This convenience is real—but it comes at the cost of dependency. Volumes exist solely within the context of the respective provider. Replication, high availability, and disaster recovery follow the provider’s architecture, not your own platform logic. Zones, regions, and failover models are predefined and only limitedly adjustable.

As long as applications remain simple, this hardly matters. However, as complexity increases, storage shifts from a supporting component to a determining factor.

When Kubernetes Becomes the Platform

Once Kubernetes is more than just an orchestrator for stateless services, the limitations of provider-specific block storage become apparent. Stateful workloads are tied to zone-specific volumes. Pod scheduling is restricted by storage topology. High availability arises not from the cluster, but from implicit assumptions about zones and regions.

Multi-cluster setups, cluster migrations, or hybrid scenarios quickly become complex or practically impossible. Storage, which should be abstracted, suddenly dictates architectural decisions. Kubernetes loses part of its promise: portability.

Longhorn: Storage as Part of the Cluster

Longhorn takes a deliberately different approach. Open source, cloud-agnostic, and fully integrated into Kubernetes. Block storage is not consumed externally but built as a distributed system directly within the cluster.

Volumes are replicated at the node level. Replication factors, placement, and failover behavior are explicitly configurable. Snapshots and backups are part of the system, not an external service. Volumes are no longer tied to zones or providers but are part of the Kubernetes logic.

The crucial difference: storage becomes a configurable architectural component again.

Control Instead of Implicit Defaults

Longhorn forces you to engage with storage. Performance characteristics, replication grades, failure scenarios, and network latencies must be consciously decided. This is additional effort—but it is transparent effort.

With provider block storage, many decisions are implicit. Defaults are adopted without being visible. Longhorn makes these decisions explicit. Operators know why a volume is replicated, how it behaves during node failures, and what performance is realistic.

This transparency is not an end in itself. It is a prerequisite for a reliable platform architecture.

Portability and True Resilience

Strategically, the biggest difference lies in the binding. Provider block storage binds data to a platform. Longhorn binds it to Kubernetes. Those who move clusters, set up new ones, or migrate between environments take their volumes with them.

This is not a marketing promise but a practical prerequisite for true resilience. Disaster recovery beyond individual providers, controlled migrations, or building redundant clusters become realistic.

Especially in scenarios where Kubernetes is understood as a long-term platform, this decoupling is crucial.

Limits and Realistic Assessment

Longhorn is not a panacea. Extremely latency-critical workloads, specialized storage hardware, or very high IOPS requirements may be better served with native provider solutions. The additional operational effort is also real and must be planned for.

For the majority of classic stateful Kubernetes workloads, however, Longhorn offers something that provider-specific block storage cannot: independence without exotic hardware or proprietary interfaces.

Condensed Comparison

When Each Approach Makes Sense

Provider block storage is sensible for:

• traditional VM workloads
• simple Kubernetes setups
• very latency-critical applications
• scenarios with conscious provider lock-in

Longhorn is sensible for:

• Kubernetes as a platform, not a byproduct
• multi-cluster or hybrid scenarios
• requirements for portability and disaster recovery
• architectures where storage follows, not dictates

Conclusion

Block storage determines availability, costs, and exit strategies. It is not a neutral infrastructure component.

Those who fully outsource it to a provider relinquish more than just data. Longhorn makes storage a configurable part of your own platform again—with all the consequences, but also with genuine control.

Resilience does not arise from defaults. It arises from conscious architectural decisions.