Patent ID: 7680844

Claim:
A computer implemented method of preserving a virtual file system, the method comprising: saving a data describing a virtual file system to a storage device, wherein the data describing the virtual file system is received from a primary data processing system, and wherein the data comprise file handle information, vnode information, and gnode information; detecting a changeover from the primary data processing system to a backup data processing system; responsive to detecting the changeover, reconstructing the virtual file system in the backup data processing system from the data stored in the storage device, wherein saving the data to a storage device comprises: saving data for a virtual file system directory to the storage device; determining whether the directory has been exported; and responsive to the directory not being exported, determining whether any changes have been made to the unexported directory; responsive to determining that changes have been made to the unexported directory, receiving second data for the unexported directory, wherein the second data comprises file handle information for the unexported directory, vnode information for the unexported directory, and gnode information for the unexported directory, wherein the second data corresponds to changes made to the unexported directory; and saving the second data to the storage device.