Patent ID: 8204863

Claim:
A computer-performed method for restoring a file system within a computer system, the method comprising: copying files to a storage containing the file system from one or more backup devices, wherein the copying is performed in multiple phases corresponding to groups of the files, wherein the copying streams the individual groups of the files in the corresponding phase in one or more file streaming operations that stream at least a portion of the groups from corresponding ones of the backup devices; receiving an on-demand access request from an entity to access a file within the file system, wherein the file is a file within a particular one of the groups; responsive to receiving the on-demand access request, determining whether or not to interrupt one of the file streaming operations to restore the file, wherein the determination is made selectively in dependence on which of the groups of files is currently being copied by the copying; in response to determining to interrupt one of the file streaming operations, selecting one of the backup devices on which to halt streaming, stopping streaming on the backup device and copying at least a portion of the file from the selected backup device to the storage; and in response to determining not to interrupt one of the file streaming operations, continuing the one or more file streaming operations, whereby the on-demand access request is delayed or denied.