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A Comprehensive Empirical Study of File Systems on Optane Persistent Memory

Emerging byte-addressable Non-volatile memories (NVM) are promising techniques as memory-like storage. Researchers have developed many NVM-aware file systems to exploit the benefits of NVM. However, many early file systems are usually evaluated based on DRAM-based simulations or emulations. Their experimental results cannot present the actual behaviors upon real NVM devices, since the devices do not perform like slow DRAMs as expected. In this paper, we provide a comprehensive empirical study of NVM-aware file systems on the first commercially available byte-addressable NVM (i.e., the Intel Optane DC Persistent Memory Module (PMM)). We evaluate and analyze the performance of the kernel-level file systems (XFS-DAX, Ext4-DAX, PMFS, and NOVA) and the user-space file systems (Strata and Libnvmmio) on PMM with various synthetic and real-world benchmarks (FIO, Filebench, FXmark, Redis, etc.). We also employ different file system configurations and different PMM configurations to evaluate their performance impact. We believe that the experimental results and performance analysis will provide implications for the developers of various applications and storage systems to reap the full characteristics of NVMs.