DiskSentry

A hacker-terminal-style desktop app that watches every drive you own — SSD, NVMe, HDD, external USB — in real time.

DiskSentry runs as a native Windows application — its own window and taskbar icon, no browser, no address bar, no console window behind it. Everything is 100% local: the app binds to 127.0.0.1 only and makes zero network calls. Nothing leaves your machine.

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✨ Features

• All your drives, live — SSD / NVMe / HDD / external USB: identity, capacity, temperature, health, real-time read/write throughput (1-second sampling), IOPS, busy%, session totals, history charts
• Who is writing — and to WHICH disk — the TOP WRITERS table ranks every running program by live write/read rate, session bytes and lifetime totals, then attributes each program to its target drive(s): your C: SSD vs. the external USB HDD. Click a row for its open file paths and per-drive split; a per-drive breakdown panel shows exactly where the writes go
• SSD TBW & endurance — lifetime host writes, rated-TBW budget bar, NAND life left, DWPD, GB/day average, burn-rate projection ("time until rated TBW at current write speed"), history that persists across restarts
• Full S.M.A.R.T. health — complete ATA attribute tables and NVMe health logs: reallocated / pending / CRC / media errors, power-on hours, power cycles, unsafe shutdowns
• USB enclosures handled — auto-probes USB-SATA bridge dialects (Innostor / JMicron / Cypress / Sunplus) and tells you honestly when an enclosure simply doesn't forward SMART
• Honest engineering — exact kernel counters vs. estimated process attribution are shown side by side; nothing is silently faked
• Zero setup — one self-contained .exe, per-user config, no install

🚀 How to use

1. Download DiskSentry.exe from the Releases page
2. Double-click it → accept the Administrator (UAC) prompt (reading raw SMART data requires elevation on Windows — the same reason CrystalDiskInfo asks for it)
3. That's it. A real app window opens. Close the window to quit — a TBW history snapshot is saved on exit.

⚠ First-run warning — SmartScreen. Because the exe is not code-signed, Windows may show "Windows protected your PC". Click More info → Run anyway. This is normal for unsigned open-source executables. Don't trust it? Build it yourself from this source in ~2 minutes.

Requirements: Windows 10/11 64-bit and an administrator account. No Python needed, no browser needed, nothing to install — the exe is fully self-contained (Windows 11 ships the WebView2 runtime built in; if it is ever missing, DiskSentry automatically opens in your default browser instead — you are never left stranded).

Want the full SMART table and exact TBW?

Install smartmontools once:

winget install smartmontools

(Default install path is auto-detected, PATH not required.) Then press RESCAN inside DiskSentry. Without smartmontools you still get all drives, health, temperature and all live I/O via PowerShell reliability counters — but the full attribute table and exact TBW numbers need smartctl.

⌨ Command line

Flag	Effect
(none)	native app window (default)
--port 9000	use another port (default 8765; if busy, a free one is picked automatically)
--browser	open the dashboard in your default browser instead of the app window
--no-browser	server only — nothing opens
--sim	demo mode with 5 simulated drives

Boot log of the windowed exe: %LOCALAPPDATA%\DiskSentry\disksentry.log. Factory reset: delete %LOCALAPPDATA%\DiskSentry\.

🖥 Reading the dashboard

Area	What it tells you
SYSTEM OVERVIEW	drive count/capacity, aggregate TBW, live read/write totals, hottest drive, overall health
PHYSICAL DRIVES	one card per drive: identity, TBW endurance bar, life/DWPD/projection chips, live I/O, temp / power-on / cycles
PROCESS I/O · TOP WRITERS	which program is reading/writing how much — live rates, session + lifetime totals, filter/sort/top-N/group-by, WRITING TO chips showing the target disk per program, click-to-expand open file paths
WHERE THE WRITES GO	per-drive breakdown: exact kernel write rate, estimated process-written share, % of all writes, top writer programs
OPEN FULL REPORT (button on each drive card)	5-tab detail panel: Overview · SMART table (searchable) · Endurance/TBW (rated editor + accrual chart) · I/O charts (60s/5m/30m) · Identity

Keyboard: R rescan · Esc closes the report panel.

🔒 Privacy

• Server binds to 127.0.0.1 only — no telemetry, no analytics, no updates phone-home, no network calls of any kind
• Config + TBW history live in %LOCALAPPDATA%\DiskSentry\ (Windows) — delete that folder for a factory reset

📦 Build from source

PyInstaller cannot cross-compile a Windows exe from Linux/macOS, so the build runs on your Windows machine — one double-click, ~2 minutes.

1. Install Python 3.10+ from https://www.python.org/downloads/ (tick "Add python.exe to PATH" on the first installer screen)
2. Double-click build_windows.bat
3. Your exe appears at build_out\DiskSentry.exe — copy it anywhere

Or run straight from source (no exe): double-click start_windows.bat, or pip install -r requirements.txt then python run.py. Works on Linux/macOS too (browser mode, drive I/O + SMART where available).

🩺 Troubleshooting (click to expand)

Symptom	Fix
SmartScreen: "Windows protected your PC"	More info → Run anyway (unsigned open-source exe) — or build it yourself
Antivirus flags the exe	PyInstaller one-file builds occasionally trip heuristics; build from source with build_windows.bat
"NO DRIVES DETECTED"	Accept the UAC prompt; run as Administrator
SMART says "smartctl not found / degraded"	winget install smartmontools, then press RESCAN
SMART tab: "Unable to detect device type"	Run as Administrator; check smartctl -a /dev/pd0 in a terminal — DiskSentry shows the exact device it used under IDENTITY → SMART DEVICE
USB drive: "enclosure does not expose SMART"	The bridge chip ignores every pass-through dialect (hardware limitation). Everything else still works; a SAT-capable dock/enclosure unlocks full SMART
Temperature/Power-on shown but SMART table empty	That's the PowerShell reliability-counter fallback (works without smartctl)
TBW shows —	HDDs have no TBW; for SSDs install smartmontools + rescan
"N protected processes hidden" in TOP WRITERS	Some system processes hide I/O counters unless elevated — relaunch as Administrator
Process rates higher than disk throughput	Windows per-process I/O counters include file, network-socket and pipe traffic (same source as Task Manager); per-disk numbers are true disk counters
"WRITING TO" shows — or hidden	No open files attributed at the last scan, or the program hides its handles — run elevated; the 40 busiest programs are scanned every 4 s
Estimated process writes < exact disk writes	Expected — the gap is OS kernel I/O, cache flushes and protected processes. Windows has no per-process-per-disk counter without ETW, so both numbers are shown side by side
Port already in use	A free port is picked automatically, or force one: DiskSentry.exe --port 9000
Prefer the browser	DiskSentry.exe --browser
No window at all	WebView2 missing (rare) — the browser fallback already opened automatically; install the Evergreen runtime from https://developer.microsoft.com/microsoft-edge/webview2/ for the native window

✅ How this is tested (click to expand)

• All 10 API endpoints exercised (live + sim, mode switching, rated-TBW save, rescan, history, events, per-process I/O)
• Real I/O verified end-to-end: a 150 MB direct write registered on the live telemetry pipeline
• Per-process attribution verified end-to-end: a live test wrote 60 MB from its own process — the tracker attributed exactly 62.9 MB to that PID's session column and attributed the sustained write stream to the drive the file lives on, with the open file path visible in the detail row
• Windows SMART path covered by an offline emulator suite (162 assertions): a fake smartctl replicating real Windows 11 machines — an NVMe laptop (serial-formatting differences included) and an Innostor USB enclosure that only answers -d sat,12 — verifies scan parsing, serial mapping, USB bridge dialect probing + persisted hints + negative caching, the PowerShell fallback and the full API surface
• Native desktop shell suite (25 checks): window URL/title/size verified with a fake webview while the backend is actually serving; a simulated WebView2 crash proves the browser fallback reuses the live backend; headless subprocesses prove the import-failure fallback chain end-to-end
• UI reviewed at 1600px and 390px: no horizontal overflow, zero console errors, keyboard navigation and reduced-motion respected

📁 Project layout (click to expand)

run.py                 entry point (native app window shell + waitress server,
                       browser fallback chain, exe log-file mirroring)
app.py                 Flask API + dashboard route
monitor/
  disks.py             physical disk enumeration (Win PS / Linux sysfs+lsblk)
  smart.py             smartctl JSON engine + PowerShell fallback + USB probing
  io_monitor.py        1s I/O sampler, 30-min ring buffers, session totals
  process_io.py        per-process I/O tracker (top writers, rates + totals,
                       open-file -> drive attribution, by-drive rollup)
  endurance.py         TBW / rated / life / DWPD / projection math
  simulator.py         SIM mode engine (5 realistic drives)
  store.py             config + TBW history persistence
  context.py           monitor singleton, background refreshers
  util.py              subprocess/PowerShell/parsing helpers
templates/index.html   dashboard page
static/style.css       spacious hacker-terminal theme
static/app.js          dashboard application (polling, panel, tabs)
static/charts.js       canvas chart engine (offline, no CDN)
build_windows.bat      one-click EXE builder (run on Windows)
DiskSentry.spec        PyInstaller spec (icon + admin manifest + datas)
scripts/               offline Windows-path test suite (fake smartctl emulator)
screenshots/           images used by this README

🚁 Publishing a release (for repo maintainers)

Two ways to get the exe onto the Releases page:

1. Automatic (recommended) — push a version tag; GitHub Actions builds the exe on a Windows runner and attaches it to a new Release:

   git tag v1.3.1
   git push origin v1.3.1
   

   (Workflow: .github/workflows/build.yml. Manual runs put the exe under the run's Artifacts instead.)
2. Manual — run build_windows.bat locally and upload build_out\DiskSentry.exe to a Release you create by hand.

Note: the exe is not code-signed, so SmartScreen will always show the "unrecognized app" prompt to new users — the README warns them above. Signing requires a certificate (OV ~$100–300/yr, EV ~$300+/yr).

📄 License

MIT — see LICENSE. DiskSentry reads your drives through psutil, smartmontools (optional) and Windows PowerShell; it never writes to your disks (aside from its own config/TBW history in %LOCALAPPDATA%).