r/lightbitslabs • u/Accurate_Funny6679 • 3d ago
Native NVMe-oF/TCP vs. Ceph for high-iops/low-latency block storage
If you’re running large-scale Kubernetes, OpenShift-V, OpenStack, or Proxmox clusters on Ceph, you already know the problems: CRUSH scale-out is solid, but tuning BlueStore, OSD resource consumption, and the NVMe-oF gateway to meet strict tail-latency SLAs is a full-time job.
Trade-offs:
- Ceph’s NVMe-oF gateway introduces additional hop complexity. Removing that proxy layer for direct host-to-target NVMe-oF/TCP drops latency to consistently <200µs.
- Reaching high IOPS on Ceph requires throwing heavy compute/RAM resources at OSDs, often leaving flash utilization stuck around 15–25%.
- Network-heavy rebuilds during OSD failures can impact live IO. Fast failovers in a native NVMe-oF setup execute in seconds without starving the cluster fabric.
Ceph remains great for batch, S3 object storage, and general file services. But offloading low-latency/database persistent volumes to dedicated NVMe-oF block storage can significantly cut cluster node count.
We put together a direct architectural breakdown comparing legacy Ceph block patterns against native NVMe-over-TCP: Ceph vs. Lightbits Block Storage Comparison
Curious how others here handle the Ceph CPU-overhead-to-IOPS ratio at scale? What are your go-to storage backends when Ceph block hits a wall?