随着OSD的更替和集群的扩缩容，PG在OSD的分布会逐渐变的不均衡，导致各OSD的实际容量使用率出现差异，集群整体使用率降低。ceph bal

🤝 Contributing We warmly welcome community contributions! Whether it’s: 📝 Architecture Knowledge: Share your Ceph architecture designs, distributed storage insights, and system design patterns 🔍 Source Code Analysis: Contribute deep-dive analysis of Ceph internals, algorithm implementations, and code walkthroughs 🛠️ Operations Practice: Share your Ceph deployment experiences, maintenance procedures, and production troubleshooting ⚡ Performance Optimization: Contribute tuning guides, benchmark results, and scalability best practices 🐛 Issue Reporting: Found documentation errors or technical issues 💡 Improvement Suggestions: Propose better organization or content ideas 🔧 Tool Contributions: Share Ceph-related monitoring, deployment, or debugging tools you’ve developed Contribution Process Fork this repository Create a feature branch: git checkout -b feature/your-feature-name Commit your changes: git commit -am 'Add some feature' Push to the branch: git push origin feature/your-feature-name Submit a Pull Request

Vision and Objectives Core Goal: Optimize I/O performance for Erasure Coded pools to be similar to Replicated Pools Primary Objectives: Lower Total Cost of Ownership (TCO) Make Erasure Coded pools viable for use with block and file storage Enabling “Optimised” EC Important Considerations Default State: All optimizations are turned off by default Per-Pool Configuration: Optimizations can be enabled for each pool individually ⚠️ Irreversible Operation: OPTIMIZATIONS CANNOT BE SWITCHED OFF once enabled Version Requirements: All OSDs, MONs, and MGRs must be upgraded to Tentacle or later Backward Compatibility: Compatible with old clients Configuration Methods Enable optimizations for a specific pool 1 ceph osd pool set <pool_name> allow_ec_optimizations true Enable optimizations by default for new pools 1 2 [mon] osd_pool_default_flag_ec_optimizations = true Key Technical Features Previously Implemented Core Features Partial Reads Partial Writes Note: Partial metadata – unwritten shards have no processing Parity Delta Writes Per-IO auto-switch between write methods Larger Default Chunk Size Direct Read Direct Write New Important Features 1.

Preface: Dominating the IO500 Rankings Having seen the DAOS project dominating the IO500 rankings, I’ve been keeping an eye on this project (though not diving deep into it). Background In previous articles, I briefly introduced the DAOS distributed storage project. However, with Intel terminating the Optane business in 2022, many people began to wonder: Can DAOS continue after losing its “core hardware support”? Where is its future? Short-term Impact, but Not the End The discontinuation of Optane did have a significant impact on DAOS, especially in metadata acceleration and persistence.

项目愿景与目标 核心目标：优化纠删码（EC）池的I/O性能，使其接近复制池的性能表现 主要目标： 降低总体拥有成本（TCO） 让纠删码池在块存储和文