https://github.com/nasty-project/nasty-top
A top-like TUI for bcachefs filesystems
https://github.com/nasty-project/nasty-top
bcachefs filesystem sysfs top tuning
Last synced: 14 days ago
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A top-like TUI for bcachefs filesystems
- Host: GitHub
- URL: https://github.com/nasty-project/nasty-top
- Owner: nasty-project
- Created: 2026-04-17T14:43:39.000Z (2 months ago)
- Default Branch: master
- Last Pushed: 2026-05-24T19:19:03.000Z (about 1 month ago)
- Last Synced: 2026-05-24T21:18:23.770Z (about 1 month ago)
- Topics: bcachefs, filesystem, sysfs, top, tuning
- Language: Rust
- Homepage:
- Size: 1.34 MB
- Stars: 10
- Watchers: 1
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# nasty-top
A top-like TUI for bcachefs filesystems. Real-time per-device IO, latency, and internal stats with built-in tuning advisor.
Built for [NASty](https://github.com/nasty-project/nasty) but works on any system with a mounted bcachefs filesystem.
## Features
- **Live IO throughput and latency** per device with user/btree/journal/sb breakdown
- **Latency from bcachefs time_stats** (EWMA rolling mean, not useless cumulative averages)
- **Per-device IO breakdown** using `io_done` JSON and `io_latency_stats_*_json`
- **Blocked stats view** showing what's actually blocking IO right now (allocator, journal, write buffer, etc.)
- **Stall detection** with 60-second event log when latency exceeds 200ms
- **Tuning hints** that flag known bcachefs pressure signals and show an example sysfs command (informational only — not applied automatically)
- **Options panel** with inline editing of runtime-tunable sysfs options
- **Multi-filesystem support** — press `f` to cycle between mounted bcachefs filesystems
- **Process IO view** showing which processes are doing IO
- **Journal fill %**, load average, reconcile progress
- **Session-aware error counts**: the device Err column dims pre-existing counts and turns bold red only when errors grow during the current run — so you can tell at a glance whether a number is dead history or actively climbing
- **Consistent color scheme**: yellow = read, blue = write, red = errors/stalls
## Install
**Nix:**
```bash
nix run github:nasty-project/nasty-top
```
**Homebrew (Linux):**
```bash
brew install fenio/tap/nasty-top
```
**Download binary:**
```bash
curl -sL https://github.com/nasty-project/nasty-top/releases/latest/download/nasty-top-x86_64-linux.tar.gz | \
sudo tar xzf - -C /usr/local/bin/
```
**Build from source:**
```bash
cargo install --path .
# or cross-compile from macOS:
brew install filosottile/musl-cross/musl-cross
rustup target add x86_64-unknown-linux-musl
./deploy.sh root@your-nas
```
## Usage
```
nasty-top [OPTIONS]
Options:
-f, --filesystem Filesystem to monitor (default: first found)
-t, --interval Refresh interval (default: 2)
-h, --help Print help
```
## Keybindings
| Key | Action |
|-----|--------|
| `?` | Toggle help popup |
| `o` | Toggle options panel (hidden by default) |
| `c` | Toggle counters view |
| `t` | Toggle blocked stats / time_stats view |
| `p` | Toggle process IO view |
| `r` | Toggle reconcile on/off |
| `g` | Toggle copygc on/off |
| `f` | Cycle between filesystems |
| `Tab` | Switch focus between metrics and options panel |
| `↑`/`k`, `↓`/`j` | Navigate options / scroll counter, blocked, process views |
| `Enter` | Edit selected option value (in options panel) |
| `Esc` | Cancel edit / dismiss status message |
| `N` | Mute current hint for 2 minutes |
| `!` | Never show this hint again |
| `C` | Clear all permanent mutes |
| `q` / `Ctrl-C` | Quit |
## Data Sources
| Metric | Source | Notes |
|--------|--------|-------|
| IO throughput | `dev-N/io_done` (JSON) | Per-type breakdown, diffed per tick |
| IO latency (device) | `dev-N/io_latency_stats_{r,w}_json` | EWMA mean, shown only when active |
| IO latency (fs) | `time_stats/data_{read,write}` | "recent" column rolling mean |
| Blocked stats | `time_stats/blocked_*` | Count delta per tick + recent mean |
| Journal fill | `internal/journal_debug` | dirty/total entries + watermark |
| Reconcile | `bcachefs reconcile status` | Subprocess, parsed for progress |
| Process IO | `/proc//io` | read_bytes/write_bytes diffed |
| Options | `options/*` | Read/write directly to sysfs |
## Tuning Hints
When known bcachefs pressure signals fire (journal fill, blocked allocator, etc.), a hint appears in the footer with a short reason and an example sysfs command you *could* run. Nothing is applied automatically — the hint is informational. The current heuristics are unverified; treat them as a starting point for investigation, not a prescription. See [TUNING_RULES.md](TUNING_RULES.md) for the full rule set.
## License
GPL-3.0-only