A virtual disk environment for providing file system recovery

File system recovery (FSR) is a kind of recovery facility that allows users to roll back the file system state to a previous state. In this paper, we present a virtual disk environment (VDE) which allows previous write operations to a hard disk to be undone, and previous version of files to be recovered. It can be used to recover the file system quickly even when computer system suffers the serious disaster such as system crash or boot failure. The VDE is same as virtual disk in the virtual machine (VM) environment in some way, but it can be applied to the environment without VM supports. Algorithms for implementing the VDE are presented and its implementation on Windows platform is discussed. Based on the implementation, the experimental results of the VDE performance are analyzed. Comparing with other FSRs, the main advantage of the VDE is low overhead and high recovery speed.