Switch to EROFS for Live Media
This document represents a proposed Change. As part of the Changes process, proposals are publicly announced in order to receive community feedback. This proposal will only be implemented if approved by the Fedora Engineering Steering Committee.
Summary
Switch the read-only filesystem image format from SquashFS to EROFS for Fedora live media.
Owner
- Name: Neal Gompa
- Email: ngompa13@gmail.com
Current status
- Targeted release: Fedora Linux 42
- Last updated: 2025-01-08
- [<link to devel-announce post will be added by Wrangler> Announced]
- [<will be assigned by the Wrangler> Discussion thread]
- FESCo issue: <will be assigned by the Wrangler>
- Tracker bug: <will be assigned by the Wrangler>
- Release notes tracker: <will be assigned by the Wrangler>
Detailed Description
In recent years, there has been increasing adoption of a new, more advanced read-only filesystem for a variety of use-cases called the Enhanced Read-Only FileSystem (EROFS). Support for EROFS as the backing read-only filesystem for live environments was introduced in Dracut v103. This change switches over all kiwi-produced live media to use EROFS instead of SquashFS.
Feedback
Benefit to Fedora
EROFS is considerably more actively developed than SquashFS, and suffers from fewer strange I/O issues (e.g. such as how squashfs-based live environments randomly freeze when using unsquashfs to install the live environment to disk). Image creation is slightly faster while maintaining similar compression levels.
Scope
- Proposal owners:
- Other developers:
- Release engineering: #12520
- Policies and guidelines: N/A (not needed for this Change)
- Trademark approval: N/A (not needed for this Change)
- Alignment with the Fedora Strategy: N/A (not needed for this Change)
Upgrade/compatibility impact
There should be no visible impact. This only affects live media used to make fresh installations.
How To Test
Once the change is applied, users can grab nightly Fedora live images that fall in scope (such as the KDE and LXQt images) to test it. Simply booting the images in a VM and installing the environment is a sufficient test.
User Experience
There should be no visible impact to users. Live installations continue to work as expected, and live environments may be slightly faster.
Dependencies
N/A. Everything has been in place and supported since Fedora Linux 41.
Contingency Plan
- Contingency mechanism: Revert back to SquashFS.
- Contingency deadline: Final Freeze.
- Blocks release? Yes.
Documentation
N/A (not a System Wide Change)
Release Notes
Fedora Linux live environments now use the Enhanced Read-Only FileSystem (EROFS), a modern, feature-rich read-only filesystem.