Image-content-aware I/O optimization for mobile virtualization

Mobile virtualization introduces extra layers in software stacks, which leads to performance degradation. Notably, each I/O operation has to pass through several software layers to reach the NAND-flash-based storage systems. This article targets at optimizing I/O for mobile virtualization, since I/O becomes one of major performance bottlenecks that seriously affects the performance of mobile devices. Among all the I/O operations, a large percentage is to update metadata. Frequently updated metadata not only degrade overall I/O performance but also severely reduce flash memory lifetime. In this article, we propose a novel I/O optimization technique to identify the metadata of a guest file system that is stored in a virtual machine image file and frequently updated. Then, these metadata are stored in a small additional non-volatile memory (NVM), which is faster and more endurable to greatly improve flash memory's performance and lifetime. To the best of our knowledge, this is the first work to identify the file system metadata from regular data in a guest OS image file with NVM optimization. The proposed scheme is evaluated on a real hardware embedded platform. The experimental results show that the proposed techniques can improve write performance to 45.21% in mobile devices with virtualization.