Ceph-Powered Hybrid Cloud Storage: Performance, Cost, and Security Insights

Hybrid Cloud Storage Trends

1. Public Cloud Storage

Unlimited Capacity: Public cloud storage scales easily, allowing users to expand capacity on demand.

Low Cost: Pay‑as‑you‑go pricing and no infrastructure investment keep costs low.

Performance not Well: Access over the public internet and shared hardware resources lead to higher latency and lower performance.

Security and Controllability not Well: Shared hardware and software under the provider’s control reduce data security and control.

2. Private Cloud Storage

High Performance: Dedicated private or leased networks and flexible hardware choices provide superior performance.

High Security and Controllability: Exclusive ownership of resources enables tighter security and control.

Limited Capacity: Scaling requires manual expansion of storage clusters, incurring significant cost.

High Cost: Capital and operational expenses for hardware, data‑center, and network are substantial.

3. Hybrid Cloud Storage

Hybrid storage combines private and public clouds, inheriting the advantages of both.

High Performance: Active data resides in private cloud, archival data in public cloud.

High Security and Controllability: Sensitive data stays in the private segment.

Unlimited Capacity: Public cloud provides virtually limitless storage.

Relatively Low Cost: Infrequently accessed data can be off‑loaded to public cloud, reducing overall cost.

Existing Solution Limitations

Ceph’s Cloud Sync (based on RGW Multisite) enables object synchronization to S3‑compatible public clouds, but it operates at the zone level, which is too coarse for many scenarios. Bucket‑level sync is available, yet still limited.

RGW Multisite Mechanism

Multisite synchronizes data across Ceph clusters using three core concepts:

zone – an independent cluster providing RGW services.

zonegroup – groups multiple zones and synchronizes data/metadata among them.

realm – a namespace containing multiple zonegroups.

Multisite works at the zone level, synchronizing all data within a zone. Bucket‑level sync offers finer granularity but still lacks object‑level control.

UMStor: Ceph‑Based Tiered Hybrid Cloud Storage Solution

Solution 1 – Object Data Storage Upgrade

Introduce Storage Class in Ceph to tier objects by media (SSD/HDD), replication factor (2‑copy, 3‑copy, Erasure Code), and even external providers (UCloud, AWS S3).

Solution 2 – Object Lifecycle Management

Implement fine‑grained lifecycle rules similar to AWS S3, enabling automatic migration of objects between storage classes (e.g., SSD→HDD, 3‑copy→2‑copy, Ceph→external cloud) and expiration.

Solution 3 – Automatic Migration Policy Generation

Analyze bucket logs to assess object “hotness” and automatically generate lifecycle rules that move cold data to cheaper storage tiers.

Future Outlook

The tiered hybrid solution meets current needs, but further work is required to support bidirectional sync and proxy read/write capabilities.

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