关键词: 迭代快照, 卷管理, 存储虚拟化

Abstract: VSVM is a logical volume manager providing an ordinary-application-oriented iterative snapshot mechanism. In VSVM, any snapshot volume can be writable. No matter how many iterative operations have been produced in generating a snapshot volume, another snapshot based on it can still be created. This ensures that snapshot data can be managed efficiently and flexibly. We introduce a direct mapping method to snapshot volume data mapping, with which the complexity of snapshot logic won’t be affected by the increase of iterative operations. This method also theoretically removes the limit of maximum number of snapshot iterative operations in design. We have implemented a VSVM prototype and analyzed its performance. Experimental results show that VSVM has nice snapshot performance; one single system can support concurrent intensive I/O on over one hundred iterative snapshot volumes. Therefore, the iterative snapshot volume is suitable for ordinary usage.

Key words: iterative snapshot, volume management, storage virtualization