Virtual-machine metadata optimization for I/O traffic reduction in mobile virtualization

Mobile virtualization introduces extra layers in software stacks, which leads to performance degradation. Especially, each I/O operation has to pass through several software layers to reach the NAND-flash-based storage systems. Among all the I/O operations, a large percentage is updating metadata. Frequent updating metadata not only degrades overall I/O performance but also severely reduces flash memory lifetime. In this paper, we propose a novel I/O optimization technique to identify the metadata of a guest file system which are stored in a VM image file and frequently updated. Then these metadata are stored in a small additional non-volatile memory which is faster and more endurable to greatly improve flash memory´s performance and lifetime. The proposed scheme is evaluated on a real hardware embedded platform. The experimental results show that the proposed techniques can effectively improve the I/O performance in mobile devices with virtualization.