We propose NVLog, an NVM-based write-ahead log for disk file systems, designed to transparently harness the high performance of NVM within the legacy storage stack. NVLog provides on-demand byte-granularity sync absorption, reserving the fast DRAM path for asynchronous operations, meanwhile occupying NVM space only temporarily. To accomplish this, we designed a highly efficient log structure, developed mechanisms to address heterogeneous crash consistency, optimized for small writes, and implemented robust crash recovery and garbage collection methods. Compared to previous solutions, NVLog is lighter, more stable, and delivers higher performance, all while leveraging the mature kernel software stack and avoiding data migration overhead. Experimental results demonstrate that NVLog can accelerate disk file systems by up to 15.09x and outperform NOVA and SPFS in various scenarios by up to 3.72x and 324.11x, respectively.

翻译：我们提出NVLog，一种基于NVM的磁盘文件系统预写日志，旨在传统存储栈中透明利用NVM的高性能。NVLog提供按需字节粒度同步吸收功能，为异步操作保留快速DRAM路径，同时仅临时占用NVM空间。为实现这一目标，我们设计了高效的日志结构，开发了应对异构崩溃一致性的机制，针对小写操作进行优化，并实现了健壮的崩溃恢复与垃圾回收方法。与现有方案相比，NVLog更轻量、更稳定且性能更优，同时充分利用成熟的内核软件栈并避免数据迁移开销。实验结果表明，NVLog可将磁盘文件系统加速最高达15.09倍，在多种场景下分别以最高3.72倍和324.11倍的优势超越NOVA与SPFS。