{
  "status": "shipping",
  "advantages": [],
  "limitations": [
    {
      "text": "Attaching a mirror member does not immediately add its full redundancy: the resilver must complete.",
      "citationIds": [
        "zattach"
      ]
    }
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-13",
  "slug": "resilver",
  "term": "Resilver",
  "aliases": [
    "ZFS resilver",
    "Resilvering"
  ],
  "definition": "A resilver is ZFS's process of bringing a newly attached, replacement or out-of-date device into agreement with the data it must hold.",
  "note": "A resilver targets data requiring synchronization; a normal full scrub checks stored data for otherwise unnoticed checksum errors [zscrub]. In OpenZFS 2.3, replacement with -s uses sequential reconstruction and starts a scrub afterward because that reconstruction does not verify checksums; this replacement mode does not support RAID-Z [zreplace].",
  "related": [
    "raid-rebuild",
    "data-scrubbing",
    "degraded-array",
    "hot-spare",
    "checksum",
    "mirroring"
  ],
  "citations": [
    {
      "id": "zscrub",
      "title": "OpenZFS 2.3: zpool-scrub(8), scrub versus resilver",
      "url": "https://openzfs.github.io/openzfs-docs/man/v2.3/8/zpool-scrub.8.html",
      "accessed": "2026-10-13"
    },
    {
      "id": "zreplace",
      "title": "OpenZFS 2.3: zpool-replace(8), replacement and sequential reconstruction",
      "url": "https://openzfs.github.io/openzfs-docs/man/v2.3/8/zpool-replace.8.html",
      "accessed": "2026-10-13"
    },
    {
      "id": "zattach",
      "title": "OpenZFS 2.3: zpool-attach(8), when a mirror gains redundancy",
      "url": "https://openzfs.github.io/openzfs-docs/man/v2.3/8/zpool-attach.8.html",
      "accessed": "2026-10-13"
    },
    {
      "id": "hesela-rebuild",
      "title": "Hesela: RAID rebuild read-error models and resilver boundaries",
      "url": "https://hesela.com/analyses/raid-rebuild-ure-math-and-resilver/",
      "accessed": "2026-10-13"
    }
  ]
}