NAS drive dataset

An original dataset of NAS and enterprise hard drives: full specs, CMR vs SMR classification, and annualized failure rates derived from Backblaze Drive Stats. 140+ drives.

The core of this dataset - the CMR/SMR classification and drive specs - is our own original research, compiled from manufacturer datasheets and model-number analysis. Manufacturers do not publish a unified CMR/SMR list; we built one. The failure-rate column enriches it with rates derived from Backblaze's raw Drive Stats data (our computation, their underlying counts).

Maintained at nasdisks.com, where the same data powers a NAS drive comparison across seven Amazon regions.

These files are a dated snapshot and may be out of date. The current, always-up-to-date dataset lives at nasdisks.com/data/ - download the latest there, or call the CORS-enabled endpoints below. Each file in data/ carries its export date in the filename so you always know how old your copy is.

What's inside

File	Rows	What it is
`data/drives-2026-06-17.csv`	140+	The headline file: one flat row per drive, all specs and failure rate combined.
`data/drives-2026-06-17.json`	140+	The same rows as JSON (mirror of the live API).
`data/cmr-reference-2026-06-17.csv`	140+	Source of truth for specs and CMR/SMR classification (including idle/seek noise and helium fill), with a per-row `confidence` flag. Our original research.
`data/backblaze-afr-2026-06-17.csv`	36	Full-year 2025 annualized failure rates, computed from Backblaze raw Drive Stats.
`data/series-reliability-2026-06-17.csv`	-	Manufacturer series specs (warranty, rated workload, MTBF) used as context where Backblaze has no data.

Quick start

The files in data/ are ready to use as-is. If you'd rather hit a live endpoint (CORS-enabled, cached, no key, no rate limit):

# JSON: { source, license, attribution, count, drives: [...] }
curl -s https://www.nasdisks.com/data/drives.json | jq '.drives[0]'

# Flat CSV
curl -s https://www.nasdisks.com/data/drives.csv

Columns (`drives-2026-06-17.csv` / `drives-2026-06-17.json`)

Column	Meaning
`model`	Manufacturer model number (e.g. `WD80EFPX`).
`brand`	WD, Seagate, Toshiba, HGST.
`line`	Product line (Red Plus, IronWolf Pro, N300, Exos, Ultrastar, etc.).
`capacity_tb`	Capacity in TB.
`rpm`	Rotational speed.
`cache_mb`	DRAM cache in MB.
`interface`	SATA or SAS.
`form_factor`	3.5 or 2.5.
`recording_tech`	`cmr` or `smr` - the field that matters most for RAID/NAS use.
`acoustic_idle_db` / `acoustic_seek_db`	Idle / seek noise as A-weighted sound power (dB), from manufacturer datasheets. Null where the maker doesn't publish it.
`is_helium`	Whether the drive is helium-sealed (`true`/`false`); null if unconfirmed.
`drive_class`	NAS, NAS-Pro, Enterprise, Surveillance, Desktop, etc.
`in_production`	Whether the drive is currently sold new.
`afr_pct`	Annualized failure rate, full-year 2025, derived from Backblaze Drive Stats (null where Backblaze doesn't track the model).
`reliability_drive_count` / `reliability_drive_days` / `reliability_failures`	The raw Backblaze figures behind `afr_pct`.
`reliability_source`	Provenance of the failure rate.

Methodology

CMR vs SMR is our original classification, built from manufacturer datasheets and model-number decoding. Manufacturers ship SMR drives into NAS lines without labelling them as such; this dataset exists because there was no single authoritative per-model reference. The confidence column in cmr-reference-2026-06-17.csv flags certainty per row.
Noise and helium are read from manufacturer datasheets (idle/seek A-weighted sound power; helium-seal designation). Our compilation; licensed CC BY 4.0 alongside the other specs.
Failure rates are computed from Backblaze's raw 2025 quarterly Drive Stats: we aggregate drive-days and failure counts across quarters into a single full-year annualized rate and validate against Backblaze's published fleet figure (~1.36% for 2025). The computation and methodology are ours; the underlying counts are Backblaze's (see licence section). Models Backblaze doesn't track are left null rather than guessed.
series-reliability-2026-06-17.csv gives manufacturer-rated context (warranty, workload TB/year, MTBF) for lines Backblaze doesn't run.

Licence & attribution

Short version: the specs and CMR/SMR data are fully open (CC BY 4.0). The failure-rate fields are free to use but must credit Backblaze and cannot be resold on their own.

1. Drive specs, CMR/SMR classification, and acoustics - CC BY 4.0

Our original work (every field except the failure-rate ones). Licensed under Creative Commons Attribution 4.0 (CC BY 4.0); full text in LICENSE.

You can: copy, modify, redistribute and build on it - including commercially.
You must: credit the source, e.g.
```
Drive specs & CMR/SMR by nasdisks.com, CC BY 4.0
```
A link back to https://www.nasdisks.com/ is enough.

2. Failure-rate data - Backblaze's terms (NOT CC BY 4.0)

The fields afr_pct, reliability_drive_count, reliability_drive_days, reliability_failures (in drives-2026-06-17.csv / drives-2026-06-17.json) and all of backblaze-afr-2026-06-17.csv are derived from Backblaze Drive Stats. The computation is ours; the underlying counts are Backblaze's.

You can: use it for free, and build (and even sell) derivative works from it.
You must: credit Backblaze as the source.
You can't: sell the raw data itself.
Backblaze does not endorse this project. Details in NOTICE.

Updates

This repo is a point-in-time snapshot; the date in each filename is its export date. For current data use nasdisks.com/data/ or the endpoints above.

Changelog

2026-06-17 - Added per-drive noise (idle / seek A-weighted sound power, dB) and helium-fill fields. Corrected WD40EZAX / WD60EZAX to CMR (the newer EZAX revision is CMR; only the older EZAZ is SMR).
2026-06-16 - Initial public dataset: full specs, CMR/SMR classification, and full-year 2025 Backblaze annualized failure rates.

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