{
  "slug": "power-aware-coding",
  "term": "Power-aware coding",
  "aliases": [],
  "definition": "Power-aware coding uses redundancy to serve selected reads without activating the disks containing the requested data.",
  "note": "An inactive symbol can be reconstructed from available symbols even when the full data word remains ambiguous [paper]. Recovery depends on the code and active set, not merely the number of parity disks [check].",
  "provenance": [
    "Greenan et al., HotDep 2008: analytical disk-energy examples, not a modern system benchmark. [paper]",
    "Hesela checks exact XOR recoverability only; no energy or lifetime measurement. [check]"
  ],
  "status": "research",
  "advantages": [],
  "limitations": [],
  "related": [
    "maid",
    "erasure-coding",
    "repair-locality",
    "locally-repairable-code"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-17",
  "citations": [
    {
      "id": "paper",
      "title": "Greenan et al.: A Spin-Up Saved is Energy Earned: Achieving Power-Efficient, Erasure-Coded Storage (HotDep 2008).",
      "url": "https://static.usenix.org/events/hotdep08/tech/full_papers/greenan/greenan_html/",
      "accessed": "2026-10-17"
    },
    {
      "id": "check",
      "title": "Hesela: Sleeping disks: one readable block is not a recoverable array.",
      "url": "https://hesela.com/analyses/sleeping-disks-partial-reconstruction/",
      "accessed": "2026-10-17"
    }
  ]
}