Abstract: A data storage system includes a storage device divided into a plurality of blocks for storing data for a plurality of volumes, and a processor to execute instructions for maintaining a block map corresponding to the data stored on the storage device. The storage system may be part of a storage system network. The block map stores reference data indicating which of the volumes reference which blocks on the storage device, and which blocks on the storage device are unallocated. The reference data may include, for groups of one or more blocks, a first value identifying the oldest volume in which the group of blocks was allocated and a second value identifying the newest volume in which the group of blocks was allocated. The volumes may include one or more snapshots.

Abstract: Parallel reconstruction of file components following a failure of one or more of the storage devices is implemented in the context of a storage system that includes a plurality of storage devices for storing file components and a plurality of metadata managers. A storage device having one or more unrecoverable read errors requiring reconstruction is identified. A metadata manager which will serve as a scheduler, and a plurality of metadata managers which serve as a plurality of workers, are identified. The plurality of workers includes metadata managers other than the scheduler. A scheduler service running on the metadata manager identified as the scheduler is used to construct a list of file components from the storage device affected by the one or more unrecoverable read errors requiring reconstruction. The scheduler service assembles a work list corresponding to each of a plurality of the workers. The work list for each worker includes a subset of file components from the list requiring reconstruction.

Abstract: A data storage system includes a storage device divided into a plurality of blocks for storing data for a plurality of volumes, and a processor to execute instructions for maintaining a block map corresponding to the data stored on the storage device. The storage system may be part of a storage system network. The block map stores reference data indicating which of the volumes reference which blocks on the storage device, and which blocks on the storage device are unallocated. The reference data may include, for groups of one or more blocks, a first value identifying the oldest volume in which the group of blocks was allocated and a second value identifying the newest volume in which the group of blocks was allocated. The volumes may include one or more snapshots.