Research and Implementation of a Snapshot Facility Suitable for Soft-Failure Recovery

Human error and incorrect software (a.k.a. soft-failure) are key impediments to dependability of Internet services. To address the challenge, storage providers need to provide rapid recovery techniques to retrieve data from a time-based recovery point. Motivated by it, a snapshot facility at the block level called SnapChain is introduced. Compared with former implementations, when managing different versions of snapshots, SnapChain minimizes disk space requirement and write penalty of master volume. In this paper, the metadata and the algorithms used in SnapChain will be explained.