NAS drive dataset

An open dataset of NAS hard drives: full specs, CMR vs SMR, and real-world Backblaze annualized failure rates (AFR). 138 drives, 13 with a measured failure rate. Our drive specs and CMR/SMR data are free to use - including commercially - under CC BY 4.0 with credit; the Backblaze failure-rate fields stay under Backblaze's own terms (cite Backblaze; don't sell the data itself).

Maintained at nasdisks.com, where the same data drives a live price comparison across seven Amazon regions.

What's inside

File	Rows	What it is
data/drives.csv	138	The headline file: one flat row per drive, specs joined to failure rate.
data/drives.json	138	The same rows as JSON (mirror of the live API).
data/cmr-reference.csv	138	Source of truth for specs + CMR/SMR classification, with a per-row confidence flag.
data/backblaze-afr.csv	36	Full-year 2025 Backblaze failure rates per model (the models Backblaze runs at scale).
data/series-reliability.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.csv / drives.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.
drive_class	NAS, NAS-Pro, Enterprise, Surveillance, Desktop, etc.
in_production	Whether the drive is currently sold new.
afr_pct	Backblaze annualized failure rate, full-year 2025 (null where Backblaze doesn't track the model).
reliability_drive_count / reliability_drive_days / reliability_failures	The raw figures behind afr_pct.
reliability_source	Provenance of the failure rate.

Methodology

• CMR vs SMR is classified from manufacturer datasheets and model-number decoding. SMR drives shingle their tracks, which cripples random-write and RAID-rebuild performance, so the distinction is the single most important spec for a NAS - and manufacturers do not always advertise it. The confidence column in cmr-reference.csv flags how certain each call is.
• Failure rates are computed from Backblaze's raw 2025 quarterly Drive Stats, aggregated to a full-year annualized rate and validated against Backblaze's own published fleet figure (~1.36% for 2025). Only the 13 catalog models that exactly match a Backblaze-tracked model carry an afr_pct; the rest are left null rather than guessed.
• series-reliability.csv gives manufacturer-rated context (warranty years, workload TB/year, MTBF) for lines Backblaze doesn't run, so you have something to reason about beyond a blank cell.

Licence & attribution

This dataset has two parts under two different sets of terms.

Drive specs + CMR/SMR classification - everything except the failure-rate fields - is our own work, released under Creative Commons Attribution 4.0 International (CC BY 4.0) (full legal code in LICENSE). Copy, remix and redistribute it, even commercially, as long as you credit:

Drive specs & CMR/SMR by nasdisks.com, CC BY 4.0

A link back to https://www.nasdisks.com satisfies it.

Failure-rate fields - afr_pct, reliability_drive_count, reliability_drive_days, reliability_failures (in drives.csv/drives.json) and the whole of backblaze-afr.csv - come from Backblaze Drive Stats and stay under Backblaze's terms, not CC BY 4.0: cite Backblaze as the source, and you may not sell the data itself (selling derivative works is fine). Backblaze does not endorse this project. See NOTICE.

Updates

The dataset is refreshed as the catalogue and Backblaze data change. The live endpoints above always reflect the current state; this repo is re-exported periodically.