Parer: Boosting EROFS Image Creation With Parallelism and Reproducibility
Yifan Zhao, Tong Xin, Mingkai Dong · 2024
The Enhanced Read-Only File System (EROFS) has become a popular choice for read-only file systems in a variety of settings, such as mobile devices and cloud services. As EROFS is increasingly applied to diverse contexts, the time-consuming process of creating EROFS images has emerged as a critical factor, often representing a bottleneck in application deployment. However, the process of parallelizing the creation of these images is fraught with challenges, owing to the constraints of fixed-size output compression, the requirement of reproducibility, and the added complexity of de-duplication features. In this paper, we introduce Parer, a parallelized version of mkfs.erofs designed to ensure reproducibility. Parer utilizes a global order-preserving mechanism to assure consistent and reproducible outcomes and employs epoch-based de-duplication to mitigate dependencies during compression. Our evaluation indicates that Parer can reduce the time of creating an EROFS image by up to 79%, while only increasing the image’s size by 3.42% on average. This work has gained recognition from the community and is being synchronized upstream.