Ext3 has been the most widely used general Linux® filesystem for many years. In keeping with increasing disk capacities and state-of-the-art feature requirements, the next generation of the ext3 filesystem, ext4, was created last year. This new filesystem incorporates scalability and performance enhancements for supporting large filesystems, while maintaining reliability and stability. Ext4 will be suitable for a larger variety of workloads and is expected to replace ext3 as the "Linux filesystem."
In this paper we will first discuss the reasons for starting the ext4 filesystem, then explore the enhanced capabilities currently available and planned for ext4, discuss methods for migrating between ext3 and ext4, and finally compare ext4 and other filesystem performance on three classic filesystem benchmarks.