EROFS explained

EROFS
Developer:Huawei originally, Alibaba Cloud, Bytedance, Coolpad, Google, OPPO
Full Name:Enhanced Read-Only File System
Introduction Os:Linux 5.4
Max Files No:Depends on volume size
Max Filename Size:255 bytes
Max Volume Size:16 TiB
Dates Recorded:File change time (extended only)
Date Resolution:1 ns
Attributes:POSIX, Extended file attributes
File System Permissions:POSIX, ACL
Compression:Yes (LZ4; LZMA since 5.16; DEFLATE since 6.6)
Data Deduplication:Yes (extent-based)
Os:Linux

EROFS (Enhanced Read-Only File System) is a lightweight read-only file system initially developed by Huawei, originally for the Linux kernel and now maintained by an open-source community from all over the world.

EROFS aims to form a generic read-only file system solution for various read-only use cases (embedded devices, containers and more) instead of just focusing on storage space saving without considering any side effects of runtime performance.

For example, it provides a solution to save storage space by using transparent compression as an option for scenarios that need high-performance read-onlyrequirements on their devices with limited hardware resources, e.g. smartphones like Android and IoT operating systems such as HarmonyOS alongside its HarmonyOS NEXT core system iteration.[1] [2] All of Huawei's new products shipped with EMUI 9.0.1 or later used EROFS,[3] and it was promoted as one of the key features of EMUI 9.1.[4] Oppo, Xiaomi and some Samsung products also use EROFS.[5] [6]

Also, it provides a content-addressable chunk-based container image solution together with lazy pulling feature to accelerate container startup speed by using new file-based fscache backend since Linux kernel v5.19.[7]

The file system was formally merged into the mainline kernel with Linux kernel v5.4.[8]

Features

The file system has two different inode on-disk layouts. One is compact, and the other is extended.

See also

External links

Notes and References

  1. Web site: There Is Finally A User-Space Utility To Make EROFS Linux File-Systems. Phoronix. Michael Larabel. 2018-11-19. 2018-12-13.
  2. erofs: introduce erofs file system. 2018-05-31. 2018-12-13. Linux kernel. Xiang. Gao.
  3. erofs: promote erofs from staging. 2019-07-04. 2019-09-03. Linux kernel. Xiang. Gao.
  4. Web site: EMUI 9.1, the Intelligent Android OS. Huawei Technologies. HUAWEI Global. 2022-01-10.
  5. Web site: Google's plan to use EROFS on Android. 20 May 2022 . 2022-08-04.
  6. Web site: The Galaxy S23 might be Samsung's first Android device to use EROFS. 2023-02-07. 2023-07-22.
  7. Web site: The Evolution of the Nydus Image Acceleration. 6 June 2022 . 2022-08-04.
  8. Web site: The 5.4 kernel has been released. corbet. 2019-11-25. LWN.net. 2019-12-01.
  9. Web site: EROFS File-System Adding LZMA Compression Support Via New MicroLZMA. Phoronix. Michael Larabel. 2022-01-10.
  10. Web site: EROFS File-System Adding DEFLATE Compression Support. Phoronix. Michael Larabel. 2023-09-03.
  11. Web site: staging: erofs: introduce LZ4 decompression inplace. 2020-12-03.
  12. Web site: staging: erofs: integrate decompression inplace. 2020-12-03.
  13. Web site: EROFS Sends In "Big Pcluster" Support For Linux 5.13, Other Improvements. Phoronix. Michael Larabel. 2021-07-11.
  14. Web site: erofs: add big pcluster compression support. 2021-07-11.
  15. Web site: XFS & EROFS File-Systems Have Big Changes For Linux 5.15. Phoronix. Michael Larabel. 2021-11-02.
  16. Web site: EROFS-Utils 1.5 Released With ZTailPacking, FSCK Extraction. 2022-08-04.
  17. Web site: 5.19 Merge window, part 1. Jonathan Corbet. 2022-08-04.
  18. Web site: Linux Kernel 5.19 Officially Released, Linus Torvalds Teases Linux 6.0 as Next Kernel Series. Marius Nestor. 31 July 2022 . 2022-08-04.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "EROFS".

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