{
  "slug": "ltfs-index",
  "term": "LTFS index",
  "aliases": [
    "LTFS XML index"
  ],
  "definition": "An LTFS index is XML metadata describing files, directories and the mapping from file contents to recorded tape extents.",
  "note": "A full index describes the volume; an incremental index records changes. Incremental indexes belong only in the data partition, whose final index must be full after clean unmount. [c1] IBM Storage Archive exposes earlier generations as rollback points. Keeping history preserves access to other generations; erase-history discards newer history, so rollback is not always reversible. [c2]",
  "status": "shipping",
  "advantages": [],
  "limitations": [
    {
      "text": "An index records file locations, not an independent backup of the file payload.",
      "citationIds": [
        "c1"
      ]
    },
    {
      "text": "Older recovery tools that do not recognize incremental indexes can fail or lose newer changes on an inconsistent volume, even when clean-volume mounting works.",
      "citationIds": [
        "c1"
      ]
    }
  ],
  "related": [
    "ltfs",
    "lto",
    "tape",
    "ltfs-data-placement-policy",
    "medium-auxiliary-memory"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-15",
  "citations": [
    {
      "id": "c1",
      "title": "SNIA LTFS Format Specification 2.5.1, sections 5.2.3, 9.2 and Annex H",
      "url": "https://www.snia.org/sites/default/files/technical-work/ltfs/release/SNIA-LTFS-Format-2-5-1-Standard.pdf",
      "accessed": "2026-10-15"
    },
    {
      "id": "c2",
      "title": "IBM Storage Archive SDE: Rolling back media",
      "url": "https://www.ibm.com/docs/en/storage-archive-sde/2.4.8?topic=tools-rolling-back-media",
      "accessed": "2026-10-15"
    }
  ]
}