Introduction

If you’re deploying OpenStack, the question of storage isn’t if—it’s how much pain you’re willing to endure.Choosing the right Ceph storage backend for OpenStack is often the difference between a stable deployment and ongoing headaches. We’ve worked with OpenStack clouds of all sizes—from small dev environments to enterprise-grade clusters with thousands of VMs—and time after time, one answer keeps surfacing:

📌 Ceph just works.
Not perfectly. Not magically. But reliably, at scale, and with far fewer regrets than the alternatives.

In this post, we’ll explore why Ceph is still the go-to storage solution for OpenStack in 2025, what pitfalls to watch for, and how to decide if it’s right for your setup.

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What Makes Ceph a Reliable Storage Backend for OpenStack?

Ceph is an open-source, software-defined storage system that provides block, object, and file storage under a unified distributed architecture. It’s not “plug and play,” but it deeply integrates with core OpenStack services:

OpenStack Component	Ceph Backend
Cinder (block)	Ceph RBD
Glance (images)	Ceph RBD
Nova (VM disks)	Boot-from-volume via RBD
Manila (file)	CephFS
Swift alternative	Ceph RGW (S3 + Swift API)

These integrations are native, well-maintained, and used in production by major OpenStack vendors including Canonical, Red Hat, and SUSE.

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Ceph Storage Backend for OpenStack: What We’ve Learned in Production

• ✅ Horizontal scaling is real
  We’ve added 200+ OSDs over 18 months without rearchitecting.
  Tip: Use device classes for performance tuning (NVMe vs HDD pools).
• ⚠️ Latency spikes during rebalance
  Especially in write-heavy environments. Monitor ceph balancer and tune osd_max_backfills carefully.
• 🔄 Snapshots are powerful but dangerous
  Don’t abuse RBD snapshots without proper trimming/flattening routines. We’ve seen 4x slowdown in clone chains >3 deep.
• 🔐 S3 + RGW is good enough (but not Swift-perfect)
  If you’re migrating from Swift, note that metadata behavior differs—especially on large listings.

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When Is Ceph the Right Storage Choice for OpenStack?

Ceph is a strong fit if:

• You’re running multi-tenant OpenStack and need flexible quotas
• You want to unify block + object storage in one platform
• You care about open source, hardware independence, and long-term maintainability
• You’re ready to invest in initial complexity for long-term reward

It’s not ideal if you:

• Only need minimal storage and want something “set-and-forget”
• Don’t have a team to monitor and maintain cluster health (or a vendor partner)
• Require ultra-low latency without NVMe-level investment

In most real-world use cases, Ceph storage backend for OpenStack offers the best balance of performance, flexibility, and operational control.

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Ceph vs Other OpenStack Storage Backends

Ceph is not the only storage backend that can work with OpenStack, but it’s the one with the widest adoption and deepest integration. Here’s how it compares to others:

🔹 Ceph vs GlusterFS

GlusterFS offers distributed file storage and is easier to get up and running—but lacks native OpenStack integration. No direct support for Cinder, Glance, or Nova.
Verdict: Suitable for simple file-serving workloads, not for enterprise-grade OpenStack.

🔹 Ceph vs Longhorn

Longhorn is elegant in Kubernetes, but not built for OpenStack’s scale or object/file workloads.
Verdict: Great for lightweight containerized setups; not fit for OpenStack storage needs.

🔹 Ceph vs Local LVM/NFS

Fast and simple, but no fault tolerance. Any hardware failure is a potential catastrophe.
Verdict: Fine for dev/test, risky in production.

🧠 TL;DR: If you need scalability, fault-tolerance, and native OpenStack integration, Ceph remains the most complete option.

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What Does Ceph Actually Cost?

Yes, Ceph is open source—but it’s not free in terms of effort or infrastructure.

🖥️ Hardware Requirements

• 3–5 OSD nodes minimum
• 10GbE network
• SSDs or NVMe for journaling
• Monitor & Manager nodes (3+ MONs recommended)

👷 Operational Effort

• Deep understanding of CRUSH maps, replication, and failure domains
• 1 FTE or managed service for cluster operations
• Monitoring with Prometheus + Grafana is essential

💸 Cost vs Enterprise SAN

Commercial SANs require per-TB licensing and support. Ceph does not. Over 3 years, Ceph clusters on commodity hardware cost up to 60–70% less than traditional SAN setups—assuming you invest in proper design and support.

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❌ Common Mistakes When Deploying Ceph with OpenStack

Here are the top pitfalls to avoid:

1. Treating Ceph Like Plug-and-Play

Fix: Understand the architecture—don’t skip CRUSH maps and replication planning.

2. Mixing HDD/SSD Without Strategy

Fix: Use dedicated pools with device_class awareness.

3. Migrating from Swift to RGW Without Testing

Fix: Validate metadata behavior, bucket indexes, and S3 API compatibility.

4. Overloading Monitor Nodes

Fix: Keep MONs on stable, low-latency hosts and always deploy an odd number for quorum.

5. No Monitoring Setup

Fix: Deploy Prometheus, Grafana, and alerting from day one.

6. Ignoring Network Design

Fix: 10GbE is a must. Separate cluster/public networks if possible.

💡 Pro tip: At Kubedo, we’ve rescued many struggling Ceph clusters. Planning early means fewer emergencies later.

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TL;DR

• Ceph is still the default storage backend for production-grade OpenStack
• It requires planning—but pays off with resilience, flexibility, and cost-efficiency
• It’s not a turnkey solution, but it’s the most complete open-source storage stack you’ll find today

For teams running OpenStack in production, choosing a Ceph storage backend for OpenStack remains the most proven strategy in 2025.

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What We Do at Kubedo

At Kubedo, we build, deploy, and manage Ceph clusters purpose-built for OpenStack:

• Architecture & performance tuning
• Hybrid cloud Ceph-Kubernetes setups
• Monitoring & alerting pipelines
• Day-2 ops: upgrades, benchmarking, disaster recovery
• RGW optimization for object-heavy environments

📩 Need help designing or operating your OpenStack storage layer?
👉 Contact us at info@kubedo.io — let’s build it right from day one.