Towards sharing disks between host OS and virtual machine with volume snapshot technology

The virtual machine technology is experiencing a resurgence of interest for diverse uses including shared hosting, server consolidation and OS compatibility. Disk sharing has been proposed to try to minimize the disk space consumption of the virtual disks. Existing disk sharing technologies on the PC platforms, however, cannot allow the host OS and the virtual machine to modify the shared disk concurrently to avoid potential data collision. To address this limitation, this paper proposes a new disk sharing mechanism to share the disk of the host OS with the virtual machine. Our approach introduces the volume snapshot technology to isolate the modification effect between the host OS and the virtual machine. In this way, we can enable the concurrent accesses to the same volumes while the data consistency can be guaranteed. The evaluation results demonstrate the feasibility of our approach while the performance evaluation shows the I/O performance achieves 89.18% of native speed on average.