{
  "slug": "dynamic-layout-score",
  "term": "Dynamic layout score",
  "aliases": [],
  "definition": "Dynamic layout score is a workload-specific locality measure based on the fraction of traced filesystem block requests that are contiguous in logical block address space.",
  "note": "Conway and colleagues used blktrace observations to include metadata and cross-file accesses, beyond a per-file layout measure. The score describes an observed access sequence, not an intrinsic property of a device.",
  "related": [
    "filesystem-aging",
    "free-space-fragmentation"
  ],
  "limitations": [
    "It does not distinguish small address gaps from large ones.",
    "It is not throughput, a percentile latency or a NAND physical-placement measurement."
  ],
  "citations": [
    {
      "id": "conway17",
      "title": "Conway et al. File Systems Fated for Senescence? Nonsense, Says Science! FAST 2017, pp. 45-58, sections 3.3, 4 and 6.",
      "url": "https://www.usenix.org/system/files/conference/fast17/fast17-conway.pdf",
      "accessed": "2026-10-14"
    }
  ],
  "status": "research",
  "advantages": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-14"
}