Boosting File Systems Elegantly: A Transparent NVM Write-ahead Log for Disk File Systems

TL;DR

NVLog is an innovative NVM-based write-ahead log that enhances disk file system performance by providing efficient crash consistency, optimized small writes, and seamless integration with existing kernel stacks, achieving significant speedups.

Contribution

It introduces NVLog, a lightweight, high-performance NVM write-ahead log that improves crash recovery, reduces overhead, and outperforms previous solutions without data migration.

Findings

Accelerates disk file systems by up to 15.09x.

Outperforms NOVA and SPFS by up to 3.72x and 324.11x.

Provides robust crash recovery and garbage collection.

Abstract

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.