{
  "slug": "disk-error-behavior-1990s-storage-prototype",
  "title": "In an 18-month Berkeley study of 368 disks, 7 data disks failed against 13 enclosure backplane failures; disks were 90% of parts but about 4% of errors",
  "kind": "dataset",
  "summary": "Talagala and Patterson (UC Berkeley, 1999) logged 18 months of a prototype with 368 SCSI data disks. 7 data disks failed (1.9%), against 13 of 46 enclosures, and disks were about 90% of parts but around 4% of errors. Cross-check rows come from Schroeder and Gibson (FAST 2007) and Ford et al. (OSDI 2010).",
  "license": "Small derived table of figures printed in Talagala and Patterson (1999), Schroeder and Gibson (FAST 2007), and Ford et al. (OSDI 2010), with credit. Not a Creative Commons license. The papers remain with their authors or publishers. This file is not a copy of the papers and not the data.",
  "licenseUrl": "https://www2.eecs.berkeley.edu/Pubs/TechRpts/1999/CSD-99-1042.pdf",
  "sourceUrl": "https://www2.eecs.berkeley.edu/Pubs/TechRpts/1999/CSD-99-1042.pdf",
  "accessed": "2026-10-11",
  "rowCount": 15,
  "columns": [
    {
      "name": "measure",
      "type": "string",
      "description": "The quantity as the source names it."
    },
    {
      "name": "value_low",
      "type": "number",
      "description": "Lower end of a printed range. Empty when the source prints a single value."
    },
    {
      "name": "value_high",
      "type": "number",
      "description": "Single printed value, or the upper end of a range. For 'over' or 'around' it is the stated figure."
    },
    {
      "name": "unit",
      "type": "string",
      "description": "Unit of the value columns: disks, months, components, percent, restarts, or years."
    },
    {
      "name": "scope",
      "type": "string",
      "description": "Population and window the value applies to."
    },
    {
      "name": "note",
      "type": "string",
      "description": "What the value is not, or the source wording behind it."
    },
    {
      "name": "citation_id",
      "type": "string",
      "description": "Id of the opened source in the citations list."
    }
  ],
  "downloadPath": "/data/datasets/disk-error-behavior-1990s-storage-prototype.csv",
  "humanPage": "https://hesela.com/analyses/disk-error-behavior-1990s-storage-prototype/",
  "limits": [
    "One small prototype built from 1996 parts; says little about modern drives.",
    "Counts are small: 7 disk failures and 1 failure for several other types.",
    "Failures are replacements over 18 months, not annual rates.",
    "The error table and the text disagree slightly on data disk errors and machine counts.",
    "The cross-check rows are other systems with other definitions."
  ],
  "citations": [
    {
      "id": "talagala-ucb99-pdf",
      "title": "An Analysis of Error Behavior in a Large Storage System, Talagala and Patterson, UC Berkeley technical report UCB/CSD-99-1042, February 1999 (author PDF, 18 pages)",
      "url": "https://www2.eecs.berkeley.edu/Pubs/TechRpts/1999/CSD-99-1042.pdf",
      "accessed": "2026-10-11"
    },
    {
      "id": "schroeder-fast07-pdf",
      "title": "Disk failures in the real world: What does an MTTF of 1,000,000 hours mean to you?, Schroeder and Gibson, FAST 2007 (USENIX PDF, section 4)",
      "url": "https://www.usenix.org/legacy/events/fast07/tech/schroeder/schroeder.pdf",
      "accessed": "2026-10-11"
    },
    {
      "id": "ford-osdi10-pdf",
      "title": "Availability in Globally Distributed Storage Systems, Ford et al., USENIX OSDI 2010 (USENIX PDF, section 3)",
      "url": "https://www.usenix.org/legacy/event/osdi10/tech/full_papers/Ford.pdf",
      "accessed": "2026-10-11"
    }
  ]
}