{
  "slug": "backblaze-2022-2025-afr-by-manufacturer",
  "title": "Backblaze hard drive AFR by manufacturer, 2022 to 2025",
  "kind": "dataset",
  "summary": "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.",
  "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.",
  "licenseUrl": "https://www.backblaze.com/cloud-storage/resources/hard-drive-test-data",
  "sourceUrl": "https://www.backblaze.com/cloud-storage/resources/hard-drive-test-data",
  "accessed": "2026-10-10",
  "rowCount": 23,
  "columns": [
    {
      "name": "year",
      "type": "integer",
      "description": "Calendar year, 2022 to 2025 (all four quarterly files of the year)."
    },
    {
      "name": "manufacturer",
      "type": "string",
      "description": "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."
    },
    {
      "name": "drive_days",
      "type": "integer",
      "description": "Daily rows (drive days) of the group in the year. This is the exposure."
    },
    {
      "name": "share_of_year_drive_days_percent",
      "type": "number",
      "description": "The group share of the All drive days in that year, one decimal."
    },
    {
      "name": "failures",
      "type": "integer",
      "description": "Rows with failure = 1 in the year."
    },
    {
      "name": "afr_percent",
      "type": "number",
      "description": "failures / drive_days * 365 * 100, two decimals. Computed here, with 365 days in every year."
    },
    {
      "name": "afr_low95",
      "type": "number",
      "description": "Lower bound of the exact two-sided 95% Poisson (Garwood) interval, in percent."
    },
    {
      "name": "afr_high95",
      "type": "number",
      "description": "Upper bound of the same interval, in percent."
    }
  ],
  "downloadPath": "/data/datasets/backblaze-2022-2025-afr-by-manufacturer.csv",
  "chartPath": "/data/datasets/backblaze-2022-2025-afr-by-manufacturer.svg",
  "citations": [
    {
      "id": "bb-data-Q12022",
      "title": "Backblaze Hard Drive Test Data, data_Q1_2022.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q1_2022.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q22022",
      "title": "Backblaze Hard Drive Test Data, data_Q2_2022.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q2_2022.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q32022",
      "title": "Backblaze Hard Drive Test Data, data_Q3_2022.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q3_2022.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q42022",
      "title": "Backblaze Hard Drive Test Data, data_Q4_2022.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q4_2022.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q12023",
      "title": "Backblaze Hard Drive Test Data, data_Q1_2023.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q1_2023.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q22023",
      "title": "Backblaze Hard Drive Test Data, data_Q2_2023.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q2_2023.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q32023",
      "title": "Backblaze Hard Drive Test Data, data_Q3_2023.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q3_2023.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q42023",
      "title": "Backblaze Hard Drive Test Data, data_Q4_2023.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q4_2023.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q12024",
      "title": "Backblaze Hard Drive Test Data, data_Q1_2024.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q1_2024.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q22024",
      "title": "Backblaze Hard Drive Test Data, data_Q2_2024.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q2_2024.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q32024",
      "title": "Backblaze Hard Drive Test Data, data_Q3_2024.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q3_2024.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q42024",
      "title": "Backblaze Hard Drive Test Data, data_Q4_2024.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q4_2024.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q12025",
      "title": "Backblaze Hard Drive Test Data, data_Q1_2025.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q1_2025.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q22025",
      "title": "Backblaze Hard Drive Test Data, data_Q2_2025.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q2_2025.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q32025",
      "title": "Backblaze Hard Drive Test Data, data_Q3_2025.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q3_2025.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-data-Q42025",
      "title": "Backblaze Hard Drive Test Data, data_Q4_2025.zip (daily CSV files)",
      "url": "https://f001.backblazeb2.com/file/Backblaze-Hard-Drive-Data/data_Q4_2025.zip",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-terms",
      "title": "Backblaze Hard Drive Test Data page and use terms",
      "url": "https://www.backblaze.com/cloud-storage/resources/hard-drive-test-data",
      "accessed": "2026-10-11"
    },
    {
      "id": "bb-2025",
      "title": "Backblaze Drive Stats for 2025 (published annual table: 115,638,676 drive days, 4,317 failures, 1.36%)",
      "url": "https://www.backblaze.com/blog/backblaze-drive-stats-for-2025/",
      "accessed": "2026-10-11"
    },
    {
      "id": "garwood",
      "title": "Garwood, F. (1936). Fiducial limits for the Poisson distribution. Biometrika 28(3-4), 437-442",
      "url": "https://doi.org/10.1093/biomet/28.3-4.437",
      "accessed": "2026-10-11"
    }
  ]
}