{
  "slug": "raidz",
  "term": "RAIDZ",
  "aliases": [
    "RAID-Z",
    "RAIDZ1",
    "RAIDZ2",
    "RAIDZ3"
  ],
  "definition": "RAIDZ is ZFS's distributed-parity virtual-device layout with one, two or three parity fragments and block-dependent stripe widths.",
  "note": "RAIDZ1, RAIDZ2 and RAIDZ3 name parity levels within this layout, not separate storage media. Single, double and triple parity protect against corresponding member-device erasures within a group when the remaining required data and metadata are readable. [concepts] Do not infer a whole-pool failure probability or usable capacity from that count alone.",
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "related": [
    "parity-raid",
    "raid-5",
    "raid-6",
    "resilver",
    "raidz-expansion"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-16",
  "citations": [
    {
      "id": "concepts",
      "title": "OpenZFS zfs-2.3.0: zpoolconcepts(7), RAID-Z virtual devices",
      "url": "https://github.com/openzfs/zfs/blob/zfs-2.3.0/man/man7/zpoolconcepts.7",
      "accessed": "2026-10-16"
    },
    {
      "id": "hesela",
      "title": "Hesela: RAIDZ expansion and retained parity cost",
      "url": "https://hesela.com/analyses/raidz-expansion-parity-capacity/",
      "accessed": "2026-10-16"
    }
  ]
}