Overcoming the Last Mile between Log-Structured File Systems and Persistent Memory via Scatter Logging
Yifeng Zhang, Yanqi Pan, Hao Huang, Yuchen Shan, Wen Xia · 2025
Log-structured file system (LFS) has been a popular option for persistent memory (PM) for its high write performance and lightweight crash consistency protocols. However, even with PM's byte-addressable I/O interface, existing PM LFSes still maintain contiguous space for log locality while using heavy garbage collection (GC) to synchronously reclaim space, causing up to 50% I/O performance degradation on PM. Thus, there exists a last-mile problem between the contiguous space management of LFS (that induces GC) and the non-contiguous byte-addressability of PM.