Issue No. 12 - December (2009 vol. 58)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TC.2009.107
Weijun Xiao , Dept. of Electr., Comput., & Biomed. Eng., Univ. of Rhode Island, Kingston, RI, USA
Qing Yang , Dept. of Electr., Comput., & Biomed. Eng., Univ. of Rhode Island, Kingston, RI, USA
Jin Ren , Dept. of Electr., Comput., & Biomed. Eng., Univ. of Rhode Island, Kingston, RI, USA
Changsheng Xie , Dept. of Comput. Eng., Huazhong Univ. of Sci. & Technol., Wuhan, China
Huaiyang Li , Dept. of Comput. Eng., Huazhong Univ. of Sci. & Technol., Wuhan, China
This paper presents a comprehensive study on implementations and performance evaluations of two snapshot techniques: copy-on-write snapshot and redirect-on-write snapshot. We develop a simple Markov process model to analyze data block behavior and its impact on application performance, while the snapshot operation is underway at the block-level storage. We have implemented the two snapshots techniques on both Windows and Linux operating systems. Based on our analytical model and our implementation, we carry out quantitative performance evaluations and comparisons of the two snapshot techniques using IoMeter, PostMark, TPC-C, and TPC-W benchmarks. Our measurements reveal many interesting observations regarding the performance characteristics of the two snapshot techniques. Depending on the applications and different I/O workloads, the two snapshot techniques perform quite differently. In general, copy-on-write performs well on read intensive applications, while redirect-on-write performs well on write intensive applications.
security of data, file organisation, Linux, Markov processes
Weijun Xiao, Qing Yang, Jin Ren, Changsheng Xie and Huaiyang Li, "Design and Analysis of Block-Level Snapshots for Data Protection and Recovery," in IEEE Transactions on Computers, vol. 58, no. 12, pp. 1615-1625, 2009.