Design and Implementation of a File Spanning among Multiple OSDs in OASIS File System

According to the development of the object based storage device (OSD) and networking technologies, some OSD based clustering file systems, for example, the ActiveScale storage cluster of the Panasas Corp. and the Lustre file system of the Cluster File System Corp., are emerging in the marketplace. Typically, these systems connect multiple OSDs on the fast network. When a large number of OSDs are connected as a linear style configuration, a client machine stores a file in its local memory first and then flushes it into an OSD. However, the file stored temporarily in the client´s memory may not be completely stored in the selected OSD because the size of the file can be bigger than that of the OSD´s available space. In this paper, we propose a detailed algorithm and system structure for solving this problem occurring in the cluster file system using OSDs.