The document summarizes updates to Ceph's Crimson storage system. Crimson uses Seastar, a library for high performance asynchronous programming, to improve the performance of Ceph's OSD (Object Storage Daemon). Specifically, Crimson avoids kernel overhead, eliminates unnecessary memory copies and context switches, and is optimized for modern storage devices. Benchmark results show Crimson significantly improves average IOPS, latency, and CPU utilization compared to the original Ceph storage design.