Ive been working on an opensource HSM (Hierarchical Storage Management) engine called HuskHoard. Most transparent storage tools on Linux use FUSE, but I found the contextswitching overhead was killing my NVMe performance for hot data. I decided to bypass FUSE and use the fanotify API to intercept file access at the kernel level instead. How it works A background janitor moves cold files to slow storage HDD/Tape/S3. It leaves a sparse husk file on the SSD. When an app tries to read the husk, HuskHoard pauses the process, recalls the data, and resumes. Its written in Rust and licensed under AGPL3.0. Github: https://github.com/huskhoard/huskhoard Technical Architecture: https://www.huskhoard.com/blog.html Im curious if anyone else here has experimented with fanotify for storage management? I'd love some technical feedback on the architecture