This is highly dependent on the filesystem - as far as I know, basically only XFS works, and only for a small subset of operations, and everything else just blo

This is highly dependent on the filesystem - as far as I know, basically only XFS works, and only for a small subset of operations, and everything else just blocks. Tokio's filesystem handling in Rust is the same way by default - a pool of IO threads. Edit: I just remembered that Avi Kivity (of KVM and ScyllaDB fame) wrote a tool to detect this: https://github.com/avikivity/fsqual https://github.com/avikivity/fsqual