{
  "slug": "background-fsck",
  "term": "Background fsck",
  "aliases": [
    "background filesystem check"
  ],
  "definition": "Background fsck is a filesystem-specific consistency-checking mode that performs permitted repairs while the filesystem remains in use.",
  "note": "The 2002 BSD design uses a snapshot and kernel-assisted reclamation. [background2002] The FreeBSD 14.3 manual requires eligible soft-updates filesystems and stops background cleaning on unexpected errors. [freebsd143]",
  "status": "shipping",
  "advantages": [],
  "limitations": [
    {
      "text": "This is not a generic permission to run an arbitrary repair tool against a mounted filesystem.",
      "citationIds": [
        "background2002"
      ]
    }
  ],
  "related": [
    "soft-updates",
    "snapshot",
    "filesystem-consistency-invariant"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "citations": [
    {
      "id": "background2002",
      "title": "McKusick. Running \"fsck\" in the Background. BSDCon 2002, pp. 55-64, sections 4-7.",
      "url": "https://static.usenix.org/events/bsdcon/mckusick/mckusick_html/index.html",
      "accessed": "2026-10-15"
    },
    {
      "id": "freebsd143",
      "title": "FreeBSD 14.3-RELEASE fsck_ffs(8): background checking, eligibility and exit status.",
      "url": "https://man.freebsd.org/cgi/man.cgi?query=fsck_ffs&sektion=8&manpath=FreeBSD+14.3-RELEASE",
      "accessed": "2026-10-15"
    },
    {
      "id": "hesela-soft",
      "title": "Hesela: Soft updates and metadata ordering",
      "url": "https://hesela.com/analyses/soft-updates-metadata-ordering/",
      "accessed": "2026-10-15"
    }
  ],
  "updated": "2026-10-15"
}