fsperf

A multithreaded filesystem performance testing tool written in OCaml that compares filesystem overhead by creating thousands of files and directories using OCaml Domains.

Features

• Multiple Filesystem Support: XFS, EXT4, ZFS, and BTRFS through pluggable backends
• Multithreaded Performance: Uses OCaml 5.x Domains for concurrent I/O operations
• Comprehensive Testing: Various workload types including random files, deep directories, many small files, and large files
• Safety Features: Device validation, mounted filesystem detection, and automatic cleanup
• CSV Export: Results can be exported for analysis and comparison

Requirements

• OCaml 5.2.1+
• Dune 3.19.1+
• Filesystem utilities:
  • XFS: xfsprogs (mkfs.xfs, xfs_admin)
  • EXT4: e2fsprogs (mkfs.ext4, tune2fs)
  • BTRFS: btrfs-progs (mkfs.btrfs, btrfs)
  • ZFS: zfsutils-linux (zpool, zfs)

Installation

# Install dependencies
opam install cmdliner mtime unix

# Build the project
dune build

# Install locally (optional)
dune install

Usage

# Basic usage
dune exec -- fsperf /dev/sdc xfs

# With custom parameters
dune exec -- fsperf /dev/sdc xfs --files 1000 --domains 4 --force-unmount --output results.csv

# Compare filesystems (run separately)
dune exec -- fsperf /dev/sdc xfs --output xfs_results.csv
dune exec -- fsperf /dev/sdc ext4 --output ext4_results.csv

Options

• --files N: Number of files to create (default varies by workload)
• --domains N: Number of concurrent domains/threads
• --force-unmount: Automatically unmount if device is mounted
• --output FILE: Export results to CSV file
• --help: Show detailed help

Architecture

Pluggable Backends: Uses OCaml functors to provide a clean interface for different filesystems, making it easy to add support for new filesystem types.

Multithreaded Execution: Leverages OCaml 5.x Domains to distribute file creation across multiple threads for realistic performance testing.

Safety First: Validates block devices, checks for existing mounts, and provides user confirmation for destructive operations.

Example Output

Filesystem: XFS on /dev/sdc
Files created: 1000
Directories created: 100
Total time: 2.34s
Files/sec: 427.35
Directories/sec: 42.74
Total ops/sec: 470.09

Development

# Run tests
dune test

# Watch mode during development
dune build --watch

# Clean build artifacts
dune clean

License

See project license file.