ZUFS - Zero-copy (Low Latency) User-mode FS

Refereed Presentation
Scheduled: Friday, September 15, 2017 from 11:00 – 11:45am in Platinum D

One Line Summary

A new interface for a new bread of User-mode filesystems that require extremely Low-Latency, synchronous, NUMA aware, DAX capable FileSystems.


FUSE enables user space file systems ever since kernel 2.6.14. It is a widely popular vehicle for rapid development and tens of file systems have used it to date. FUSE is asynchronous in nature and heavily relies on the operating system page cache. It was designed with hard drive latency in mind and was measured to add penalty of 12.5 to 1000 micro second [us], depending on the load.

Emerging persistent memory technologies, such as NVDIMM-N and 3D XPoint / MRAM / ReRAM based NVDIMM, operate at near memory speed and require a different user space file system mechanism. One that is tuned to latency.

The motivation of this work is to enable new bread of User-mode work, based on above Technologies that typically respond within a single micro second – faster than any caching, redundant data copying and queuing.

ZUFS, pronounced Zoo-FS and stands for Zero-copy User-mode FS is a new kernel project designed to fill that gap.

ZUFS is designed from the get go to provide an example of a full, PMEM based, FS, to demonstrate Speed, behavior and correctness. But the motivation is that not only full flagged Filesystems need apply. Any other User-Mode Service that wants to very effectively with modern direct mmapped access, service many applications and can enjoy a filesystem like interface. Can enjoy this new ABI from Kernel.
The emphasis here is on multi-threaded, Low Latency, synchronous, Zero copy, direct mapped type access from the application to the Server-Application. And vise versa direct mapping of Server resources into the application.

All this without sacrificing security or robustness.

And how we think we can do this? Please see the attached paper, and come to our talk. But mainly this is more of an open question then a ready made proposal.

Have a good day



FUSE. FileSytem. Persistent memory

Presentation Materials



  • Boaz_by_sagi


    Currently employed by Plexistor

    Computer hacker since 1989,

    On Linux Kernel mostly storage and filesystems since 2006.

    Previously also worked on Wine for a while.

    Was always working in an Hardware+Software real time projects, also have experience in hardware programing in VHDL.

    28 years is a long time, did alot of stuff….