Patent ID: 7024427
Filing Date: 2006-04-04
Classification: G06F

Abstract:
1. A method for virtualizing a plurality of underlying file systems hosted on one or more file servers, wherein each file system includes a storage space in which a plurality of data files may be stored comprising: aggregating the storage spaces of said plurality of file systems into a single virtual storage space that is exported as a virtual volume that appears to clients as local file system; creating a virtual volume directory and file name hierarchy including a virtual pathname for each data file stored in the virtual volume; providing a software virtualization layer including both client-side and server-side software components that cooperatively enable clients to access data files stored in the virtual volume through reference to the virtual pathnames for those data files; and maintaining a copy of system configuration information that identifies the file server used to host a master logical volume and one or more file servers hosting one or more slave logical volumes on each client that accesses the virtual file system, wherein clients that access data files stored in the virtual volume do not need to know the file servers and pathnames under which those data files are actually stored; for each file in the virtual name directory and file hierarchy, data separate from the file system data of the underlying file system is associated with the virtual directory and file name hierarchy, the data including a metadata and a pointer to the file contents stored in one or more underlying file systems; data describing the virtual volume directory and file name hierarchy is stored in the master logical volume corresponding to one of said underlying file systems; and the data files corresponding to the virtual pathnames in the virtual volume are stored in the one or more slave logical volumes corresponding to at least one of said plurality of underlying file systems.