{
  "slug": "chunk-fragmentation",
  "term": "Chunk fragmentation",
  "aliases": [
    "deduplication fragmentation"
  ],
  "definition": "Chunk fragmentation is the dispersion of chunks needed by a deduplicated restore across storage containers or an order poorly matched to the restore sequence.",
  "note": "Sparsity and repeated container visits are different costs; this is not NAND erase-block fragmentation. [fu2014]",
  "related": [
    "deduplication",
    "container-capping",
    "forward-assembly-area"
  ],
  "citations": [
    {
      "id": "fu2014",
      "title": "Min Fu, Dan Feng, Yu Hua, Xubin He, Zuoning Chen, Wen Xia, Fangting Huang and Qing Liu. Accelerating Restore and Garbage Collection in Deduplication-based Backup Systems via Exploiting Historical Information. USENIX ATC 2014, pp. 181-192; sections 3-6.",
      "url": "https://www.usenix.org/system/files/conference/atc14/atc14-paper-fu_min.pdf",
      "accessed": "2026-10-11"
    },
    {
      "id": "hesela-dedup-restore",
      "title": "Deduplication ratio does not predict restore cost",
      "url": "https://hesela.com/analyses/deduplication-restore-fragmentation/",
      "accessed": "2026-10-11"
    }
  ],
  "status": "research",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-11"
}