erofs

erofs(5) File Formats Manual erofs(5)

NAME

   erofs - the Enhanced Read-Only File System

DESCRIPTION

   erofs is a create-once read-only filesystem, with support for compression and a multi-device backing store.

   There are two inode formats:

     32-byte compact with 16-bit UID/GID, 32-bit file size, and no file times
     64-byte extended with 32-bit UID/GID, 64-bit file size, and a modification time (st_mtim).

Mount options

   user_xattr
   nouser_xattr
          Controls whether user extended attributes are exposed.  Defaults to yes.

   acl
   noacl  Controls whether POSIX acl(5)s are exposed.  Defaults to yes.

   cache_strategy=disabled|readahead|readaround
          Cache allocation for compressed files: never, if reading from start of file, regardless of position.  Defaults to readaround.

   dax
   dax=always|never
          Direct Access control.  If always and the source device supports DAX, uncompressed non-inlined files will be read directly, without going through the page cache.  dax is a syn
          onym for always.  Defaults to unset, which is equivalent to never.

   device=blobdev
          Add extra device holding some of the data.  Must be given as many times and in the same order as --blobdev was to mkfs.erofs(1).

   domain_id=did
   fsid=id
          Control CacheFiles on-demand read support.  To be documented.

VERSIONS

   erofs images are versioned through the use of feature flags; these are listed in the -E section of mkfs.erofs(1),

CONFIGURATION

   Linux must be configured with the CONFIG_EROFS_FS option to mount EROFS filesystems.  There are sub-configuration items that restrict the availability of some of the parameters above.

SEE ALSO

   mkfs.erofs(1), fsck.erofs(1), dump.erofs(1)

   Documentation/filesystems/erofs.txt in the Linux source.

Linux man-pages 6.9.1 2024-05-02 erofs(5)