Abstract: Techniques and systems for storing and retrieving data storage devices of a data storage system are disclosed. In some embodiments, inventory holders are used to store data storage devices used by a data storage system. When data is to be transacted with the data storage devices, mobile drive units locate appropriate inventory holders and transport them to a device reading station, where an appropriate device retrieval unit transacts the data. In some embodiments, each inventory holder includes a plurality of trays that are independently accessible to the device retrieval unit. After the data has been transacted, the data storage devices are returned to the appropriate inventory holders, and the inventory holders are placed by the mobile drive units in locations where they may be accessed in response to further data transactions.

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: An enclosure-based tape drive server, comprises an enclosure, a controller, a memory linked to the controller, a plurality of at least eight tape drives, a host bus adapter and a network controller. The controller is positioned within the enclosure. The at least eight tape drives are positioned within the enclosure, and each of the tape drives is accessible from a front side of the enclosure. The host bus adapter couples the plurality of tape drives to the controller. The network controller is connectible to a network to couple the server to the network.

Abstract: Techniques and systems for storing and retrieving data storage devices of a data storage system are disclosed. In some embodiments, inventory holders are used to store data storage devices used by a data storage system. When data is to be transacted with the data storage devices, mobile drive units locate appropriate inventory holders and transport them to a device reading station, where an appropriate device retrieval unit transacts the data. The inventory holders are configured such that any of the mobile drive units may interchangeably interact with any of the inventory holders and/or the data device reading stations. After the data has been transacted, the data storage devices are returned to the appropriate inventory holders, and the inventory holders are placed by the mobile drive units in locations where they may be accessed in response to further data transactions.

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.