Abstract: Reciprocal data storage protection is combined with “N+1” hardware provisioning and on-demand resynchronization to guarantee full data availability without impairing performance. Pairs of nodes are identified that act as backups for each other, where each node stores a secondary copy of data allocated to its reciprocal, paired node. A single extra node is brought online to take over the role of a failed node and assumes the role of the primary node it replaced.

Abstract: Reciprocal data storage protection is combined with “N+1” hardware provisioning and on-demand resynchronization to guarantee full data availability without impairing performance. Pairs of nodes are identified that act as backups for each other, where each node stores a secondary copy of data allocated to its reciprocal, paired node. A single extra node is brought online to take over the role of a failed node and assumes the role of the primary node it replaced.

Abstract: A networked digital data processing system has two or more client devices, a network including a set of interconnections for transferring information between the client devices, at least one of which has a local data file storage element for locally storing and providing access to digital data files arranged in one or more client filesystems. A migration file server includes a migration storage element that stores data portions of files from the client devices, a storage level detection element that detects a storage utilization level in the storage element, and a level-responsive transfer element that selectively transfers data portions of files from the client device to the storage element.

Abstract: An improved backup storage system and method for use in conjunction with hierarchical or mass storage servers and networks is disclosed. Baseline, full and incremental backup procedures are used to save file copies. In one preferred embodiment, the baseline backup procedure is used to store copies of stable files, i.e. files that are modified less frequently, if at all. With a hierarchical storage server, such files are typically those stored on tertiary storage media, e.g. erasable optical disks, WORMs or magnetic tape. The full backup procedure stores, as full backup copies, copies of all files not in the baseline backup and files that have been changed since the time of their baseline backup. The full backup procedure also stores file identifiers and signal representative of storage locations of baseline backup copies for files which have not been changed since the time of the baseline backup.