{
  "slug": "lustre-hsm",
  "term": "Lustre HSM",
  "aliases": [
    "Lustre hierarchical storage management"
  ],
  "definition": "Lustre HSM coordinates file-data archival, release and restoration between a Lustre filesystem and an external storage backend.",
  "note": "Per-file flags describe different properties, not one mutually exclusive label. EXISTS records a backend copy; DIRTY marks divergence. ARCHIVED can coexist with DIRTY: the command manual itself shows that combination. Read the full flagset before inferring that a copy is current. [lustre-hsm-manual] [lustre-hsm-state]\n\nA successful archive-completion report records the supplied data version, sets ARCHIVED and clears DIRTY and LOST. A state query returns stored metadata without fetching backend payloads. Neither operation is an independent byte-level restore check. [lustre-hsm-completion] [lustre-hsm-state]",
  "status": "shipping",
  "related": [
    "lustre-hsm-release",
    "cold-archive",
    "backup",
    "restore-test"
  ],
  "advantages": [],
  "limitations": [],
  "citations": [
    {
      "id": "lustre-hsm-manual",
      "title": "Lustre v2_17_0: lfs-hsm(1), state flags and dirty+archived example",
      "url": "https://github.com/lustre/lustre-release/blob/4b0407a48e9e5b7f17877e8868080e9f40c238c6/Documentation/man1/lfs-hsm.1",
      "accessed": "2026-11-04"
    },
    {
      "id": "lustre-hsm-state",
      "title": "Lustre v2_17_0: mdt_hsm_state_get and mdt_hsm_state_set",
      "url": "https://github.com/lustre/lustre-release/blob/4b0407a48e9e5b7f17877e8868080e9f40c238c6/lustre/mdt/mdt_hsm.c",
      "accessed": "2026-11-04"
    },
    {
      "id": "lustre-hsm-completion",
      "title": "Lustre v2_17_0: archive completion and restore/remove compatibility checks",
      "url": "https://github.com/lustre/lustre-release/blob/4b0407a48e9e5b7f17877e8868080e9f40c238c6/lustre/mdt/mdt_coordinator.c",
      "accessed": "2026-11-04"
    }
  ],
  "updated": "2026-11-04",
  "provenance": [
    "Pinned Lustre v2_17_0 source review, commit 4b0407a48e9e5b7f17877e8868080e9f40c238c6; no running-cluster or backend recovery test.",
    "Replayable source ledger and isolated flag-helper check: https://hesela.dev/research/lustre-hsm/README.md"
  ],
  "supersedes": [],
  "supersededBy": []
}