Abstract: Techniques described and suggested herein include systems and methods for storing, indexing, and retrieving original data of data archives on data storage systems using redundancy coding techniques. For example, redundancy codes, such as erasure codes, may be applied to archives (such as those received from a customer of a computing resource service provider) so as allow the storage of original data of the individual archives available on a minimum of volumes, such as those of a data storage system, while retaining availability, durability, and other guarantees imparted by the application of the redundancy code. Sparse indexing techniques may be implemented so as to reduce the footprint of indexes used to locate the original data, once stored.

Abstract: Techniques described and suggested herein include systems and methods for storing, indexing, and retrieving original data of data archives on data storage systems using redundancy coding techniques. For example, redundancy codes, such as erasure codes, may be applied to archives (such as those received from a customer of a computing resource service provider) so as allow the storage of original data of the individual archives available on a minimum of volumes, such as those of a data storage system, while retaining availability, durability, and other guarantees imparted by the application of the redundancy code. Sparse indexing techniques may be implemented so as to reduce the footprint of indexes used to locate the original data, once stored.

Abstract: Techniques for producing incremental short-term backups while minimizing media access are described herein. A backup request is received that specifies data to backup and a schedule for that backup. The data is then partitioned based on the schedule and, for each of the partitions, it is determined whether to store a full or incremental backup of that partition. Each partition is fully backed up once during a cycle of backups and incrementally backed up at other times. With each full backup of a partition, a reverse delta that can be used to reconstruct the previous full backup for that partition is stored with the full backup.

Abstract: A data center may include a tape library rack module along with rack computer systems. The rack computer systems may be configured to provide computing capacity within a data center environment. In some embodiments, the tape library rack module may include an enclosure encompassing an interior of the tape library rack module, a rack within the interior, and a tape library unit mounted on the rack. The tape library rack unit may include tape cartridges configured to store data within a tape environment that is different than the data center environment. The tape library rack unit may be within a portion of the interior that is enclosed such that it is environmentally isolated from the data center environment. In some examples, the tape library rack module may include a cooling unit and/or a humidifier unit, which may provide the tape environment to the environmentally isolated portion of the interior of the tape library rack module.

Abstract: Techniques for encoding data storage systems using grid-encoded data storage systems with non-parity linear redundancy encoding schemes are described herein. A grid of shards with derived shards and data shards is generated that is indexed by a first index and a second index and is configured so that each shard is reproducible from other shards with the same first index and is also reproducible from other shards with the same second index. The grid of shards is further configured so that each data row of the grid of shards has at least two derived shards and at least twice as many data shards as derived shards.

Abstract: Techniques for rebundling grid encoded data storage systems are described herein. A new grid of shards is created based in part on shards from a first grid of shards. The second grid of shards contains data shards, including one or more data shards from the first grid of shards, and derived shards that are indexed by row and column and is configured so that shards in the second grid are reproducible from shards in the same row using a first redundancy code and are also reproducible from shards in the same column using a second redundancy code. The derived shards of the second grid of shards are then derived from other shards in the second grid of shards using the first redundancy code and the second redundancy code.

Abstract: Techniques described and suggested herein include systems and methods for storing, indexing, and retrieving original data of data archives on data storage systems using redundancy coding techniques. For example, redundancy codes, such as erasure codes, may be applied to archives (such as those received from a customer of a computing resource service provider) so as allow the storage of original data of the individual archives available on a minimum of volumes, such as those of a data storage system, while retaining availability, durability, and other guarantees imparted by the application of the redundancy code. Sparse indexing techniques may be implemented so as to reduce the footprint of indexes used to locate the original data, once stored.

Abstract: Techniques for exploiting variable media sizes to create new redundancy encoded data storage systems are described herein. A set of storage devices is selected based at least in part on each storage device having an available capacity and, using the set of storage devices, a set of shards for a redundancy encoded data storage system is generated such that each shard of the set of shards has a storage capacity corresponding to the minimum available capacity of the set of storage devices.

Abstract: Techniques for storing data on a tape using a heterogeneous data storage technique are described herein. A logical partition from a logical model of a data storage tape is associated with a set of data. If a current location of the data storage tape corresponds to the logical partition of the set of data, a first data transfer operation associated with the set of data is performed using the data storage tape. The data transfer operation is monitored and changes to the data transfer rate of the data transfer operation are used to update the logical extent of the tape and to update the logical model. If the current location of the data storage tape does not correspond to the logical partition of the set of data, the data set is staged for later storage.

Abstract: Techniques for incrementally increasing media size in data storage systems using grid encoded data storage techniques are described herein. A grid of shards is created where each shard of the grid of shards has a first index, a second index and each shard also has an associated storage device configured with a storage capacity that is large enough to store the largest set of data on a shard. Upon determining to replace the storage devices of the grid with storage devices that have a different storage capacity, the storage devices can be incrementally replaced within the grid by first padding each shard of the grid of shards with a set of data values, replacing a data shard storage device with a device of the different storage capacity, and replacing a set of derived shard storage devices with devices of the different storage capacity.

Abstract: A data center may include a tape library rack module along with rack computer systems. The rack computer systems may be configured to provide computing capacity within a data center environment. In some embodiments, the tape library rack module may include an enclosure encompassing an interior of the tape library rack module, a rack within the interior, and a tape library unit mounted on the rack. The tape library rack unit may include tape cartridges configured to store data within a tape environment that is different than the data center environment. The tape library rack unit may be within a portion of the interior that is enclosed such that it is environmentally isolated from the data center environment. In some examples, the tape library rack module may include a cooling unit and/or a humidifier unit, which may provide the tape environment to the environmentally isolated portion of the interior of the tape library rack module.

Abstract: A data storage service distributes a plurality of data fragments corresponding to a data object among one or more data storage host groupings in a manner that avoids a possibility of correlated loss of multiple data fragments by consolidation of data of a data storage host grouping onto a single data storage host. The data storage service selects a data storage host grouping and determines an amount of used capacity for the selected data storage host grouping. If the selected grouping satisfies an emptiness threshold, the data storage service selects a data storage host from the grouping and consolidates one or more data sets of the grouping onto the selected data storage host. Subsequently, the data storage service updates metadata for each data storage host of the selected data storage host grouping to specify a location of data stored therein.

Abstract: Techniques described and suggested herein include systems and methods for storing, indexing, and retrieving original data of data archives on data storage systems using redundancy coding techniques. For example, redundancy codes, such as erasure codes, may be applied to archives (such as those received from a customer of a computing resource service provider) so as allow the storage of original data of the individual archives available on a minimum of volumes, such as those of a data storage system, while retaining availability, durability, and other guarantees imparted by the application of the redundancy code. Sparse indexing techniques may be implemented so as to reduce the footprint of indexes used to locate the original data, once stored. The volumes may be apportioned into failure-decorrelated subsets, and archives stored thereto may be apportioned to such subsets.

Abstract: Erasure encoded fragments are generated by an erasure encoding scheme, represented by an erasure encoding matrix, operating on a data file. A new erasure encoded fragment may be generated from previously-generated erasure encoded fragments without reconstructing the original data file. Available and valid erasure encoded fragments are identified and a set of those fragments is selected. A composite encoding matrix is generated based upon the selected fragments and the fragment specified to be generated. The composite matrix is applied to the selected fragments to produce a plurality of partial sums. The partial sums are then combined to generate the specified fragment. The partial sums may be produced by different devices so as to distribute the computational workload and/or to reduce network traffic. The integrity of a generated fragment may be verified by generating the specified fragment twice, using two different sets of fragments, and then comparing the two results.

Abstract: Techniques for incrementally increasing media size in data storage systems using grid encoded data storage techniques are described herein. A grid of shards is created where each shard of the grid of shards has a first index, a second index and each shard also has an associated storage device configured with a storage capacity that is large enough to store the largest set of data on a shard. Upon determining to replace the storage devices of the grid with storage devices that have a different storage capacity, the storage devices can be incrementally replaced within the grid by first padding each shard of the grid of shards with a set of data values, replacing a data shard storage device with a device of the different storage capacity, and replacing a set of derived shard storage devices with devices of the different storage capacity.

Abstract: Techniques described and suggested herein include systems and methods for storing, indexing, and retrieving original data of data archives on data storage systems using redundancy coding techniques. For example, redundancy codes, such as erasure codes, may be applied to archives (such as those received from a customer of a computing resource service provider) so as allow the storage of original data of the individual archives available on a minimum of volumes, such as those of a data storage system, while retaining availability, durability, and other guarantees imparted by the application of the redundancy code. Sparse indexing techniques may be implemented so as to reduce the footprint of indexes used to locate the original data, once stored. The volumes may be apportioned into failure-decorrelated subsets, and archives stored thereto may be apportioned to such subsets.

Abstract: Techniques described and suggested herein include systems and methods for precomputing regeneration information for data archives (“archives”) that have been processed and stored using redundancy coding techniques. For example, regeneration information, such as redundancy code-related matrices (such as inverted matrices based on, e.g., a generator matrix for the selected redundancy code) corresponding to subsets of the shards, is computed for each subset and, in some embodiments, stored for use in the event that one or more shards becomes unavailable, e.g., so as to more efficiently and/or quickly regenerate a replacement shard.

Abstract: Techniques described and suggested herein include systems and methods for storing, indexing, and retrieving original data of data archives on data storage systems using redundancy coding techniques. For example, redundancy codes, such as erasure codes, may be applied to archives (such as those received from a customer of a computing resource service provider) so as allow the storage of original data of the individual archives available on a minimum of volumes, such as those of a data storage system, while retaining availability, durability, and other guarantees imparted by the application of the redundancy code. Sparse indexing techniques may be implemented so as to reduce the footprint of indexes used to locate the original data, once stored. The volumes may be apportioned into failure-decorrelated subsets, and archives stored thereto may be apportioned to such subsets.

Abstract: Techniques described and suggested herein include systems and methods for precomputing regeneration information for data archives (“archives”) that have been processed and stored using redundancy coding techniques. For example, regeneration information, such as redundancy code-related matrices (such as inverted matrices based on, e.g., a generator matrix for the selected redundancy code) corresponding to subsets of the shards, is computed for each subset and, in some embodiments, stored for use in the event that one or more shards becomes unavailable, e.g., so as to more efficiently and/or quickly regenerate a replacement shard.

Abstract: Diverse erasure encoded fragments, that is, fragments produced by different erasure encoding schemes, may be used to reconstruct a data file. The diverse erasure encoded fragments for the data file are collected and the erasure encoding schemes used to generate the fragments are identified. A fragment matrix is generated from these fragments. An expanded encoding matrix is generated based upon the identified erasure encoding schemes. One or more rows may be removed from the expanded matrix to generate a square matrix. If the square matrix is invertible then it is inverted to provide a decoding matrix. One or more corresponding rows may be removed from the collected fragment matrix. The decoding matrix and the collected fragment matrix are multiplied to recover the data file. Padding symbols may be added to one or more fragments so that all fragments have the same number of symbols per fragment.