Single-host disk diagnostics in your terminal. The terminal you open when the disk light won't stop blinking — before you reach for iostat, iotop, smartctl, lsblk, df, du, and a panic.
Sibling to NetWatch and SysWatch. Same chrome. Same palette. Eight tabs covering every disk on one box.
| # | Tab | Replaces |
|---|---|---|
| 1 | Overview | one screen across capacity, IO, health, hot files |
| 2 | Devices | lsblk, nvme list, diskutil list, hdparm -I |
| 3 | Volumes | lvs + vgs, mdadm --detail, diskutil apfs list |
| 4 | FS | df -h, df -i, mount, findmnt |
| 5 | IO | iostat -x 1, biolatency-style averages |
| 6 | SMART | smartctl -A, nvme smart-log |
| 7 | Hot Files | fanotify/fseventsd watcher (paths, not bytes) |
| 8 | Insights | plain-English anomaly summaries |
Where lsblk shows you which disks exist, DiskWatch shows you what's happening on them — capacity trending, IO throughput, p99 latency, SMART health, and the files being written right now — and tells you why in plain English when something's anomalous.
git clone https://github.com/matthart1983/diskwatch.git && cd diskwatch
cargo build --release
./target/release/diskwatchOr from crates.io:
cargo install diskwatchPrerequisites: Rust 1.75+. No system dependencies on Linux. macOS calls the standard ioreg, diskutil, and system_profiler binaries — all preinstalled. Optional: smartmontools (brew install smartmontools / apt install smartmontools) for full SMART attribute tables — without it, the SMART tab falls back to the basic verified/failing flag from diskutil.
| Key | Action |
|---|---|
1–8 |
Switch tabs |
↑ / ↓ / j / k |
Move selection (Devices, FS) |
p |
Pause / resume sampling |
q / Esc |
Quit |
--diag |
Print collected state and exit (no TUI) |
[1] Overview — 5 KPI tiles (capacity, IO, p99 latency, health, insights), per-device summary, aggregate IO sparkline, top insights, segmented capacity bar.
[2] Devices — block-device table with model, firmware, serial, used %, SMART status. Detail panel for the selected device.
[3] Volumes — APFS containers (macOS) with nested volumes, role, mount, FileVault. mdraid arrays (Linux) with members, slot state [UUUU], resync/recovery progress.
[4] FS — mounted filesystems with inline usage bars, threshold colors, system/user/removable classification.
[5] IO — per-device read / write throughput, 48s sparkline, p50 + p99 latency (read and write) over a 60s rolling window.
[6] SMART — full NVMe / ATA attribute tables when smartctl is on PATH; degraded banner with install instructions when not. Always shows the basic verified/failing flag.
[7] Hot Files — paths by event rate via FSEvents (macOS) / inotify (Linux). Honest footer: this tab can't show bytes/sec or process attribution without root (fs_usage) / Endpoint Security entitlement / eBPF biosnoop.
[8] Insights — anomaly cards over the collected state: capacity warnings, SMART failures, NVMe wear, drive temperature, p99 latency outliers, IO-dominant devices, hot-file runaway, removable drives.
| Metric | macOS | Linux |
|---|---|---|
| Device model / serial / firmware | ✅ system_profiler + IOKit |
✅ /sys/block/*/device/{model,serial,firmware_rev} |
| Per-device used bytes | ✅ via APFS container map | ✅ summed from sysinfo mounts |
| Read/write byte rates (split) | ✅ IOKit Statistics |
✅ /proc/diskstats cols 5/9 |
| Avg per-op latency | ✅ Total Time / Operations |
✅ /proc/diskstats cols 6/10 |
| p50 / p99 latency | ✅ tick-averaged over 60s | ✅ tick-averaged over 60s |
| True per-op p99 (histogram) | ❌ needs IOReport entitlement | ❌ needs eBPF biolatency (CAP_BPF) |
| SMART attributes | ✅ smartctl if installed |
✅ smartctl if installed |
| Volumes — APFS | ✅ diskutil apfs list |
n/a |
| Volumes — mdraid | n/a | ✅ /proc/mdstat |
| Volumes — ZFS, LVM | ⏳ deferred | ⏳ deferred |
| Hot files (paths) | ✅ FSEvents | ✅ inotify |
| Hot files — bytes / pid | ❌ needs root fs_usage / entitlement |
❌ needs eBPF biosnoop |
Inherits the *Watch family chrome — #0c1418 background, terminal-green accent, JetBrains Mono, 130×36 character grid with responsive reflow ≥ 110×30. The same character-grid mockups that drive NetWatch and SysWatch drive DiskWatch.
- Not multi-host. Use NetWatch Cloud if you need a fleet view.
- Not a daemon. No long-running collector, no persisted DB.
- Not a deduper / cleaner. We surface what's eating disk; we don't delete anything. Mutation is a different tool.
- Not a backup product. Snapshots are observed, not authored.
- Not a benchmark. We measure what's happening, not what's possible.
MIT.