{
  "slug": "erofs",
  "term": "EROFS",
  "aliases": [
    "Enhanced Read-Only File System"
  ],
  "definition": "EROFS is a Linux read-only filesystem for prepared images, with optional transparent file-data compression.",
  "note": "The Linux v6.16 documentation describes both uncompressed and compressed data layouts, inline tail packing and fragments. mkfs.erofs prepares images; selecting EROFS does not require compression. [erofs]\n\nRead-only filesystem access is separate from authenticating the image. In a block-backed deployment, dm-verity can verify accessed blocks against a trusted root hash; the format name alone does not establish that protection. [verity]\n\nIn EROFS fixed-sized output compression, the compressed physical cluster and the variable-sized uncompressed extent are different units. The v6.16 manual dates larger physical clusters to Linux v5.13; 4 KiB is not a universal compressed-cluster limit. [erofs]",
  "status": "shipping",
  "advantages": [
    {
      "text": "Optional compression and multiple data layouts allow image construction to fit different read-only uses.",
      "citationIds": [
        "erofs"
      ]
    }
  ],
  "limitations": [
    {
      "text": "Feature and decompressor support must match the reader; this record does not rank runtime performance.",
      "citationIds": [
        "erofs"
      ]
    }
  ],
  "related": [
    "squashfs",
    "read-only-mount",
    "dm-verity",
    "transparent-compression"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-23",
  "citations": [
    {
      "id": "erofs",
      "title": "Linux v6.16: EROFS overview and on-disk data layouts",
      "url": "https://docs.kernel.org/6.16/filesystems/erofs.html",
      "accessed": "2026-10-23"
    },
    {
      "id": "verity",
      "title": "Linux v6.16: dm-verity trust and on-demand verification",
      "url": "https://docs.kernel.org/6.16/admin-guide/device-mapper/verity.html",
      "accessed": "2026-10-23"
    }
  ],
  "provenance": [
    "Version-pinned documentation review; no image-mount experiment or comparative benchmark."
  ]
}