Dataset · 2022 to 2025 · computed from raw Backblaze files

Backblaze hard drive AFR by manufacturer, 2022 to 2025

Yearly annualized failure rate of Backblaze's hard drives for Seagate, HGST, Toshiba and WDC, computed from the raw daily Drive Stats files for 2022 to 2025 (sixteen quarterly zips) with exact 95% Poisson intervals. Sample: drives of 3 TB or more, 388,670,883 drive days and 16,051 failures over the four years. Pooled AFR was 1.39% in 2022, 1.70% in 2023, 1.59% in 2024 and 1.36% in 2025. HGST went from 0.63% in 2022 to 3.01% in 2024 and 2.89% in 2025. One fleet, and the file does not say why rates moved.

File /data/datasets/backblaze-2022-2025-afr-by-manufacturer.csv · JSON metadata · Chart (SVG) · All datasets · AFR glossary entry

Population and method

Population: hard drives of 3 TB or more in Backblaze’s own data centers, from the daily Drive Stats files for January 1, 2022 to December 31, 2025 (sixteen quarterly zips, 1,461 daily files). That is 388,670,883 drive days and 16,051 failures. Each daily row is one drive day and a row with failure = 1 is a failure.

The manufacturer comes from the model-name prefix: ST is Seagate; HGST, HUH and HMS are HGST; TOSHIBA is Toshiba; WDC, WUH and WD are WDC. The one legacy model that matches none of them, Hitachi HDS5C4040ALE630, is in the Other row and holds a few thousand drive days a year. AFR is failures ÷ drive days × 365 × 100, with 365 used for 2024 too. The interval is the exact two-sided 95% Poisson interval. The build checks that the manufacturers add up to the All row of each year.

Cross-check: Backblaze’s annual reports give 1.70% for 2023 and 1.36% for 2025, and this file gives the same two numbers. Its 2022 and 2024 figures (1.39% and 1.59%) are close to but not the same as the published ones, because Backblaze removes boot drives and drives that miss its annual criteria and this file keeps every row of 3 TB or more.

Chart

Counted here

• Pooled AFR was 1.39% in 2022, 1.70% in 2023, 1.59% in 2024 and 1.36% in 2025.
• HGST went from 0.63% (0.56% to 0.71%) in 2022 to 3.01% (2.83% to 3.19%) in 2024 and 2.89% in 2025, while its share of drive days fell from 20.4% to 8.9%.
• Seagate fell from 2.02% to 1.58% and from 49.6% of drive days to 34.6%. Toshiba was 1.25% in 2025 on 32.8% of drive days. WDC rose from 0.18% to 0.64% and from 6.7% to 23.8% of drive days.

Limits

• Association only, one fleet. The file shows how each maker’s rate moved from year to year. It does not say why, and it cannot separate a maker from the models, ages and capacities Backblaze happened to buy from it. A maker’s row can be driven by a few models.
• The mix changed over the four years, so pooled changes mix a change in rates with a change in which makers hold the drive days.
• Manufacturer comes from model-name prefixes, and the Other row is not a maker. Backblaze retires drives for reasons other than failure, which this file cannot see.
• Intervals assume failures are Poisson in drive days with a constant rate inside each year, which ignores clustering. They are probably too narrow.

Table

Columns

year (integer)

Calendar year, 2022 to 2025 (all four quarterly files of the year).

manufacturer (string)

Seagate, HGST, Toshiba, WDC or Other, from the model-name prefix (ST; HGST, HUH, HMS; TOSHIBA; WDC, WUH, WD). Other is the legacy model Hitachi HDS5C4040ALE630 and holds a few thousand drive days. All is every hard drive of 3 TB or more.

drive_days (integer)

Daily rows (drive days) of the group in the year. This is the exposure.

share_of_year_drive_days_percent (number)

The group share of the All drive days in that year, one decimal.

failures (integer)

Rows with failure = 1 in the year.

afr_percent (number)

failures / drive_days * 365 * 100, two decimals. Computed here, with 365 days in every year.

afr_low95 (number)

Lower bound of the exact two-sided 95% Poisson (Garwood) interval, in percent.

afr_high95 (number)

Upper bound of the same interval, in percent.

License

Derivative table computed from the Backblaze Drive Stats daily files for 2022 to 2025. Cite Backblaze if you use it. You are solely responsible for how you use it. Backblaze's dataset page allows sale of derivative works and forbids selling the Drive Stats data itself. This CSV is a 23-row aggregate, not the daily SMART archive, and that archive is not for sale.

Backblaze Drive Stats use terms · Hard Drive Test Data page

Sources

1. Backblaze Hard Drive Test Data, data_Q1_2022.zip (daily CSV files) (accessed 2026-10-11)
2. Backblaze Hard Drive Test Data, data_Q2_2022.zip (daily CSV files) (accessed 2026-10-11)
3. Backblaze Hard Drive Test Data, data_Q3_2022.zip (daily CSV files) (accessed 2026-10-11)
4. Backblaze Hard Drive Test Data, data_Q4_2022.zip (daily CSV files) (accessed 2026-10-11)
5. Backblaze Hard Drive Test Data, data_Q1_2023.zip (daily CSV files) (accessed 2026-10-11)
6. Backblaze Hard Drive Test Data, data_Q2_2023.zip (daily CSV files) (accessed 2026-10-11)
7. Backblaze Hard Drive Test Data, data_Q3_2023.zip (daily CSV files) (accessed 2026-10-11)
8. Backblaze Hard Drive Test Data, data_Q4_2023.zip (daily CSV files) (accessed 2026-10-11)
9. Backblaze Hard Drive Test Data, data_Q1_2024.zip (daily CSV files) (accessed 2026-10-11)
10. Backblaze Hard Drive Test Data, data_Q2_2024.zip (daily CSV files) (accessed 2026-10-11)
11. Backblaze Hard Drive Test Data, data_Q3_2024.zip (daily CSV files) (accessed 2026-10-11)
12. Backblaze Hard Drive Test Data, data_Q4_2024.zip (daily CSV files) (accessed 2026-10-11)
13. Backblaze Hard Drive Test Data, data_Q1_2025.zip (daily CSV files) (accessed 2026-10-11)
14. Backblaze Hard Drive Test Data, data_Q2_2025.zip (daily CSV files) (accessed 2026-10-11)
15. Backblaze Hard Drive Test Data, data_Q3_2025.zip (daily CSV files) (accessed 2026-10-11)
16. Backblaze Hard Drive Test Data, data_Q4_2025.zip (daily CSV files) (accessed 2026-10-11)
17. Backblaze Hard Drive Test Data page and use terms (accessed 2026-10-11)
18. Backblaze Drive Stats for 2025 (published annual table: 115,638,676 drive days, 4,317 failures, 1.36%) (accessed 2026-10-11)
19. Garwood, F. (1936). Fiducial limits for the Poisson distribution. Biometrika 28(3-4), 437-442 (accessed 2026-10-11)