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Modern FS Benchmark
What Modern FS Benchmark is
Modern FS Benchmark is a free Linux, self-hosted benchmark for comparing multi-device copy-on-write filesystems such as btrfs, ZFS, and bcachefs with ext4 and XFS baselines. Its phases measure throughput, latency, snapshots, compression, reflinks, redundancy layouts, encryption, fsync latency, degraded operation, rebuilds, corruption recovery, and near-full behavior. Results are published in a dashboard with per-metric charts, aging curves, run trends, filters, and a sortable table. GitHub Actions runs benchmarks on every push and every six hours using four loop devices backed by sparse files. Because hosted devices share one virtual disk, absolute throughput is meaningless there and RAID-striping gains are fictional. Local Linux runs can use loop devices or real block devices. Real-device runs wipe listed devices, which must be unmounted; existing filesystem signatures require BENCH_WIPE=1. The corruption phase overwrites a raw range on one device, scrubs, and checks one tracked-file hash, not whole-filesystem health. Workload recipes and the composite index are project-specific. Source uses Apache 2.0; datasets use CC BY 4.0.
Who it suits
It suits Linux users and storage teams comparing filesystem behavior through repeatable self-hosted or CI runs. Operators using real hardware must be prepared for destructive device wiping.
What it does well
- Covers throughput, latency, and IOPS
- Provides dashboard charts and filters
- Runs through GitHub Actions
- Supports real block-device benchmarks
- Includes filesystem integrity and recovery phases
What to know first
- Real-device runs wipe listed devices
- Hosted CI throughput is not meaningful
- Methodology is not industry-standard
- Corruption test is not a whole-filesystem check
Verdict
Modern FS Benchmark offers broad filesystem workload coverage and dashboarded results for Linux environments. Its project-specific methodology and destructive real-device procedure require careful interpretation and setup.
Facts from Modern FS Benchmark's own pages
- Benchmark coverage
- Its measurements include redundancy layouts, snapshots, compression, encryption, reflinks, fsync latency, degraded operation, rebuilds, corruption recovery, and near-full behavior. · github.com, 4 Oct 2026
- CI cadence
- GitHub Actions runs benchmarks on every push and on a six-hour schedule using four loop devices backed by sparse files. · github.com, 4 Oct 2026
- CI limitation
- Hosted CI devices share one virtual disk, so the project says absolute throughput is meaningless and RAID striping gains are fictional in those runs. · github.com, 4 Oct 2026
- Destructive operation
- Real-device runs require unmounted devices, refuse devices with filesystem signatures unless BENCH_WIPE=1 is set, and wipe listed devices. · github.com, 4 Oct 2026
- Hardware runs
- The scripts can run against real block devices, which are wiped when listed for a benchmark run; devices must be unmounted and existing filesystem signatures require BENCH_WIPE=1. · github.com, 4 Oct 2026
- Hardware support
- The maintainer says a suitable dedicated server currently costs approximately €70 per month, depending on availability and disk configuration, and invites hardware support or sponsorship. · github.com, 4 Oct 2026
- Integrations
- The project runs benchmarks in GitHub Actions and provides a reusable NixOS module and benchmark package for self-hosted runners. · github.com, 4 Oct 2026
- Integrity coverage
- The project describes checksum verification and reconstruction testing for btrfs, ZFS, and bcachefs when redundancy is configured. · github.com, 4 Oct 2026
- Licensing
- Source code, configuration, workflows, and documentation use Apache License 2.0, while published benchmark datasets use CC BY 4.0. · github.com, 4 Oct 2026
- Linux deployment
- The repository provides a Nix flake with a reusable NixOS module and benchmark package for dedicated self-hosted GitHub Actions runners. · github.com, 4 Oct 2026
- Local use
- The README documents running the benchmark locally on Linux with loop devices or on real block devices. · github.com, 4 Oct 2026
- Maintainer
- The repository copyright identifies Bartosz Fenski; it does not state a headquarters or founding date. · github.com, 4 Oct 2026
- Methodology limitation
- The README says its workload recipes and composite summary index are project-specific rather than an industry-standard benchmark. · github.com, 4 Oct 2026
- Methodology limits
- The exact workload recipes and composite summary index are project-specific rather than an industry-standard benchmark. · github.com, 4 Oct 2026
- Project licenses
- The source code, configuration, workflows, and documentation use Apache License 2.0; published benchmark datasets use CC BY 4.0. · github.com, 4 Oct 2026
- Purpose
- Modern FS Benchmark continuously benchmarks multi-device copy-on-write filesystems, including btrfs, ZFS, and bcachefs, against ext4 and XFS baselines. · github.com, 4 Oct 2026
- Results dashboard
- Results are published in a dashboard with per-metric charts, aging curves, run trends, filters, and a sortable table. · github.com, 4 Oct 2026
- Security and data integrity
- The corruption phase overwrites a raw range on one device, runs a scrub, and compares a tracked test-file hash; the README cautions that this is not a whole-filesystem health check. · github.com, 4 Oct 2026
- Security scope
- The corruption test overwrites a raw range on one device, scrubs, and checks one tracked file hash; it is not a whole-filesystem health check. · github.com, 4 Oct 2026
- Sponsor support
- The maintainer says a suitable dedicated server costs approximately €70 per month and accepts financial support through GitHub Sponsors and Ko-fi. · github.com, 4 Oct 2026
- Support
- The maintainer invites issues and pull requests for workload, configuration, methodology, and filesystem suggestions. · github.com, 4 Oct 2026
- Workloads
- Its benchmark phases measure throughput, latency, snapshots, compression, reflinks, degraded operation and rebuild, corruption recovery, and near-full behavior. · github.com, 4 Oct 2026
Where Modern FS Benchmark stands on Freedom251
- Disk Benchmark Software#26 of 29