Filesystem Layout Reorganization in Virtualized Environment

Reorganization of storage data layout is a famous I/O performance improvement method. Many methods have been studied. These methods improve I/O performance by reducing storage seek distances. In virtualized environment, a storage device has several huge image files. Thus, I/O performance is severely decreased by many long distance seeks among these files. Accordingly, I/O performance is expected to be significantly improved by reorganizing data layout in this environment. However, existing reorganizing methods were published before virtualized environment has emerged and take no account of virtualized environment. Thus, the existing methods cannot improve I/O performance largely in virtualized environment. In this paper, we present performance evaluation of the existing reorganizing methods in virtualized environment. After that, we propose a reorganizing method suitable for virtualized environment. Finally, we demonstrate that the propose method outperforms the existing methods with experiments.