erofs - Linux

Overview

erofs is a command-line tool for manipulating Enhanced Read-Only File Systems (EROFS). An EROFS is a compressed, read-only file system designed for high-performance read operations, often used in embedded systems and other scenarios where fast boot times and minimal storage space are crucial.

Syntax

erofs [options] <command> [<command-args>]

Options/Flags

  • -h, –help: Print usage information and exit.
  • -V, –version: Print version information and exit.
  • -v, –verbose: Enable verbose output.
  • -q, –quiet: Suppress all output except for errors.
  • -z, –compression-level: Set the compression level (0-9).
  • -b, –block-size: Set the block size (default: 4096 bytes).
  • -s, –inodes-per-block: Set the number of inodes per block (default: 16).
  • -d, –device: Specify the device node or file to operate on.

Examples

Create an EROFS

erofs -z 3 -b 8192 -s 32 -d /dev/sda1 create /path/to/erofs.img

Mount an EROFS

mount -t erofs /path/to/erofs.img /mnt/erofs

Unmount an EROFS

umount /mnt/erofs

Check EROFS integrity

erofs -v check /path/to/erofs.img

Common Issues

  • EROFS file system not found: Ensure that the specified device or file exists and is formatted as an EROFS.
  • Insufficient space: Ensure that the target device or file has enough space to accommodate the EROFS.
  • Permission denied: Check that you have sufficient permissions to create, mount, or unmount the EROFS.

Integration

erofs can be integrated with other tools for advanced tasks, such as:

  • mke2fs: Create an EROFS image using a kernel-provided library.
  • mkfs.ext4: Create an EROFS image using the ext4 file system library.
  • dd: Copy an EROFS image to or from a device or file.

Related Commands

  • mount: Mount an EROFS file system.
  • umount: Unmount an EROFS file system.
  • e2fsck: Check the integrity of an EROFS file system.