According to Esper's recent report , the latest beta version of Android 13 includes two new feature announcements, which show that Google is planning to bring EROFS to Android 13, making it the default read-only file system. The file system was developed by Huawei. Compared with existing file systems, EROFS has obvious advantages, which can significantly save storage space and bring speed and performance improvements.
EROFS is an acronym for Enhanced Read-Only File System, originally developed by Huawei. In mid-2018, EROFS was first introduced to the staging area of Linux kernel version 4.14, and after a year of continuous development, the EROFS file system driver was merged into the mainline in Linux kernel version 5.4. EROFS was first released in EMUI 9.1 in 2019, and the first models to use the technology were the Huawei P30 and P30 Pro. This is also Huawei's last flagship product series to support GMS.
Unlike other read-only file systems, EROFS is designed to build a new file management system that improves disk performance and speed while saving disk space to reduce unnecessary usage. According to Huawei, the random read speed of the EROFS file system can be increased by 20% on average, and even up to 200%, which greatly improves system efficiency compared with traditional EXT4.
Google is now only planning to make it the default filesystem for read-only partitions, such as those used by the core of the Android system. Since the system partition is usually read-only, compressing the system partition can reduce the space footprint to save space for files that only change during system updates.
While Google will enable the EROFS read-only file system in Android 13, that doesn't mean all devices will automatically use it. This change will only affect devices that come out with Android 13 by default, and those devices also require built-in GMS. Therefore, this change in Android 13 will not have any impact on users and manufacturers using AOSP.