erofs · shipping · also Enhanced Read-Only File System

EROFS

EROFS is a Linux read-only filesystem for prepared images, with optional transparent file-data compression.

Related Observatory article: EROFS on hesela.com

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. [1]

Read-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. [2]

In 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. [1]

Relations

related

SquashFS, Read-only mount, dm-verity, Transparent filesystem compression

Advantages

• Optional compression and multiple data layouts allow image construction to fit different read-only uses. [1]

Limitations

• Feature and decompressor support must match the reader; this record does not rank runtime performance. [1]

Citations

1. Linux v6.16: EROFS overview and on-disk data layouts (accessed 2026-10-23)
2. Linux v6.16: dm-verity trust and on-demand verification (accessed 2026-10-23)

JSON: /data/terms/erofs.json