Why Ceph Becomes a Liability When You Use It to Replace vSAN

Teams replacing vSAN after a VMware exit share a common early decision: the storage budget is gone, the Broadcom licensing cost is the trigger, and the question is what replaces it without a new commercial bill. Ceph appears at the top of every shortlist. It is production-proven, widely deployed, and carries no licensing fee. For a team looking at the numbers at the start of the project, Ceph is the rational default.

The problem is that vSAN’s cost is not primarily licensing. The cost vSphere admins understand is the annual renewal. The cost Ceph surfaces is engineering time: the hours spent on cluster operations, failure recovery, and upgrades. That second cost does not appear in a spreadsheet comparison, and it does not show up until the first production incident.

Why VMware Teams Default to Ceph After Leaving vSAN

The case for Ceph as a vSAN replacement is straightforward. Ceph is a mature distributed storage system with a strong open-source ecosystem. Rook deploys and lifecycle-manages Ceph clusters on Kubernetes using standard operator patterns. Block storage via RBD plugs directly into Kubernetes through the Rook-Ceph CSI driver.

From a capability standpoint, Ceph matches most of what vSAN provided. RBD gives block storage with replication. CephFS adds shared filesystem support. RADOS Gateway covers object storage. CRUSH map-based failure domain configuration handles rack and zone awareness. The feature surface is there.

The first year of operations is where the comparison breaks down.

What Ceph Operational Complexity Looks Like in the First Year

Ceph’s documentation is thorough. Its community is large. Neither fact eliminates the expertise requirement for running a production cluster. Three operational areas cause the most friction for VMware teams who were not Ceph specialists before the migration.

Monitor quorum recovery. Ceph monitors maintain cluster state through a consensus protocol. A three-monitor cluster is the minimum for production quorum. When monitor store corruption occurs, recovery requires reconstructing the monitor store from data held in OSDs: a multi-step procedure involving manual CLI operations on the monitor filesystem, setting specific flags on the monitor map, and restarting services in a defined sequence. The Ceph project publishes detailed walkthroughs for exactly this failure scenario because the procedure is non-trivial enough to require documentation. A vSphere admin encountering this failure mode for the first time, without Ceph expertise in-house, is facing a potentially extended outage.

OSD lifecycle and CRUSH maps. Adding capacity to a Ceph cluster means adding OSDs. Removing a drive or a node means marking OSDs out, waiting for rebalancing to complete, and then removing the OSD from the cluster. Every change to the cluster topology interacts with CRUSH maps that control data placement. Teams migrating from vSAN are accustomed to a vCenter wizard that handles this; Ceph requires CLI fluency and familiarity with how placement rule changes affect rebalancing across the cluster.

CephFS capacity management. Reclaiming storage capacity in CephFS involves snapshot tree awareness and transcoding operations that require understanding CephFS internal semantics. The Ceph project publishes capacity reclamation procedures for CephFS that presuppose deep CephFS expertise. For teams that primarily ran block workloads on vSAN, adding a CephFS-dependent workflow introduces a new knowledge surface.

These are not edge cases. They are the Day 2 operations that every production Ceph cluster eventually requires.

Running Ceph to replace vSAN and hitting the operational complexity wall? Simplyblock’s managed NVMe/TCP eliminates DIY Ceph cluster operations while delivering NVMe-native performance on Kubernetes, bare-metal, and any hypervisor. Talk to a storage architect

The vSAN Capabilities Teams Lose When Moving to Ceph

The operational comparison matters, but so does the capabilities gap. vSAN provided integrated management, automated storage policy enforcement, and a centralized health model that vCenter exposed directly to platform teams. Ceph provides the primitives; teams build the operations layer themselves.

The table below maps vSAN capabilities against their Ceph and simplyblock equivalents across the dimensions that matter most after migration:

Table 1: vSAN, Ceph/Rook, and simplyblock compared across Day 2 operational dimensions.

The pattern across the Ceph column is consistent: Ceph provides the capability, but the team provides the operational expertise to exercise it safely. For a platform team with existing Ceph specialists, this is acceptable. For a team that was exclusively vSphere-skilled before the migration, each of these cells represents a knowledge gap that will surface under pressure.

Managed NVMe/TCP as the Alternative to DIY Ceph

The architectural case for disaggregated NVMe/TCP is distinct from the Ceph operational comparison, but the two address the same question: what does a team with Kubernetes-native requirements and no appetite for distributed storage specialization actually need?

Disaggregated NVMe/TCP separates the storage tier from compute. Storage nodes expose NVMe volumes over a TCP fabric; Kubernetes nodes mount them without the storage controller running locally. The result: cluster scaling, failure isolation, and capacity management apply to the storage tier independently of the compute tier. Adding compute nodes does not require rebalancing storage. Adding capacity does not require a Kubernetes node change.

simplyblock’s control plane manages the NVMe fabric, volume placement, replication, and failure recovery without requiring cluster administrator intervention on storage internals. There is no monitor quorum to manage, no OSD lifecycle to sequence, and no CRUSH map to edit when topology changes. The CSI driver exposes VolumeSnapshot, StorageClass, and thin provisioning natively. Prometheus metrics are available without configuring a separate Ceph dashboard stack.

The pricing model is capacity-based: per usable TB per year, with no per-core licensing. A vSAN team moving away from Broadcom’s per-core model is already familiar with the pain of compute-anchored pricing. NVMe/TCP capacity pricing scales with storage provisioned, not with cores added or compute nodes deployed.

For platform teams that reached Ceph via the “free storage” path and are now measuring the engineering hours against the savings, the comparison is not licensing versus zero. It is licensing plus managed operations versus zero licensing plus DIY operations at full engineering cost. That framing often changes the conclusion. The best vSAN alternatives in 2026 depend on the team’s operating model as much as the technical requirements, and for teams that cannot staff Ceph specialists, managed NVMe/TCP over standard TCP is worth evaluating before committing to a DIY cluster. For teams choosing between NVMe/TCP and NVMe/RoCE, NVMe/TCP’s compatibility with any Ethernet switch and any hypervisor makes it the lower-friction path for VMware refugees who are already rebuilding their platform stack.

Questions and Answers

Is Ceph a good replacement for vSAN after a VMware exit?

Ceph can replace vSAN’s capabilities but not vSAN’s operational model. vSAN’s management surface is integrated with vCenter; Ceph requires a separate operational discipline. Teams with existing Ceph expertise can make this work well. Teams migrating from a vSphere-only background will typically spend the first 6 to 12 months building operational muscle in production. The right vSAN alternative depends on the team’s operating model as much as the technical requirements.

What makes Ceph operationally complex for teams coming from vSphere?

Ceph’s complexity is architectural. Monitor quorum management, OSD lifecycle sequencing, CRUSH map configuration, and BlueStore tuning require domain-specific knowledge that vSphere admins do not carry over from their previous environment. Routine procedures like adding capacity, recovering from a monitor failure, or reclaiming storage in CephFS all require CLI familiarity with Ceph internals. These are Day 2 operations on any production cluster, not rare edge cases.

How does simplyblock differ from Ceph for Kubernetes persistent storage?

Simplyblock is a disaggregated NVMe/TCP storage platform with a managed control plane. It exposes Kubernetes-native storage via a CSI driver with native VolumeSnapshot support, without requiring teams to operate distributed storage internals. There is no monitor quorum, no OSD lifecycle, and no CRUSH map management. The storage tier scales independently from the compute tier.

Does simplyblock support Rook-style Kubernetes-native deployment?

Simplyblock deploys as a Kubernetes operator with a CSI driver, similar in lifecycle pattern to Rook. The key difference is that simplyblock’s control plane is managed, so there is no Ceph cluster reconciliation loop running in your cluster. StorageClass, VolumeSnapshot, and PVC lifecycle work identically to any CSI-compliant driver.

What is the total cost difference between Ceph and managed NVMe/TCP storage?

Ceph’s license cost is zero. simplyblock licenses per usable TB per year, with no per-core fee. The comparison is zero licensing plus DIY engineering cost versus per-TB licensing plus managed operations. Teams that have measured the engineering hours consumed by Ceph administration typically find the managed cost competitive once DIY operations are fully loaded. The pricing model also removes the per-core exposure that made Broadcom’s vSAN licensing a migration trigger in the first place.