Abstract: A method for providing enhanced readability of data written to a magnetic tape, includes the steps of (i) writing data to a first tape partition using a tape drive, the data being written under a first dimensional stability condition; (ii) monitoring an ambient dimensional stability condition with a condition monitor to determine if the ambient dimensional stability condition has moved at least a predetermined threshold value from the first dimensional stability condition toward a preferred dimensional stability condition; and (iii) replicating the data to a second tape partition with a data replicator when it has been determined that the ambient dimensional stability condition has moved at least the predetermined threshold value from the first dimensional stability condition toward the preferred dimensional stability condition.

Abstract: A method for ensuring data quality integrity on a magnetic tape includes the steps of writing object data to the magnetic tape; dividing the object data into a plurality of data chunks; generating a hash tree from the plurality of data chunks, the hash tree being formed in a plurality of levels, the hash tree including (i) a plurality of chunk hashes wherein a separate chunk hash is generated for each of the plurality of data chunks, and (ii) at least one second level hash that is generated from concatenation of at least two of the plurality of chunk hashes; and checking integrity of a first data chunk of the plurality of data chunks by evaluating at least one of the plurality of chunk hashes and the at least one second level hash.

Abstract: A method for providing enhanced readability of data written to a magnetic tape, includes the steps of (i) writing data to a first tape partition using a tape drive, the data being written under a first dimensional stability condition; (ii) monitoring an ambient dimensional stability condition with a condition monitor to determine if the ambient dimensional stability condition has moved at least a predetermined threshold value from the first dimensional stability condition toward a preferred dimensional stability condition; and (iii) replicating the data to a second tape partition with a data replicator when it has been determined that the ambient dimensional stability condition has moved at least the predetermined threshold value from the first dimensional stability condition toward the preferred dimensional stability condition.

Abstract: A magnetic tape device or system can store erasure encoded data that generates a multi-dimensional erasure code corresponding to an erasure encoded object comprising a code-word (CW). The multi-dimensional erasure code enables using a single magnetic tape in response to a random object/file request, and correct for an error within the single magnetic tape without using other tapes. Encoding logic can further utilize other magnetic tapes to generate additional parity tapes that recover data from an error of the single magnetic tape in response to the error satisfying a threshold severity for a reconstruction of the erasure coded object or chunk(s) of the CW. The encoding logic can be controlled, at least in part, by one or more iterative coding processes between multiple erasure code dimensions that are orthogonal to one another.

Abstract: A magnetic tape device or system can store erasure encoded data that generates a multi-dimensional erasure code corresponding to an erasure encoded object comprising a code-word (CW). The multi-dimensional erasure code enables using a single magnetic tape in response to a random object/file request, and correct for an error within the single magnetic tape without using other tapes. Encoding logic can further utilize other magnetic tapes to generate additional parity tapes that recover data from an error of the single magnetic tape in response to the error satisfying a threshold severity for a reconstruction of the erasure coded object or chunk(s) of the CW. The encoding logic can be controlled, at least in part, by one or more iterative coding processes between multiple erasure code dimensions that are orthogonal to one another.

Abstract: Methods and apparatus associated with storing data in high or low energy zones are described. Example apparatus include a data storage system (DSS) that protects a message using an erasure code (EC). A location in the DSS may have an energy efficiency rating or a latency. Example apparatus include logics that produce an EC that has a likelihood of use, that select a location to store the EC in the DSS based on the energy efficiency rating, the latency, or the likelihood of use, that store the EC in the location, and that compute an order of retrieval for an EC stored in the location. The order of retrieval may be based on the energy efficiency rating or the latency. The EC may also have a priority based on the number of erasures for which the EC corrects.

Abstract: Methods, apparatus, and other embodiments associated with adaptive use of erasure codes for distributed data storage systems are described. One example method includes accessing a message, where the message has a message size, selecting an encoding strategy as a function of the message size, data storage device failure statistics, data storage device wear periods, data storage space constraints, or overhead constraints, and where the encoding strategy includes an erasure code approach, generating an encoded message using the encoding strategy, generating an encoded block, where the encoded block includes the encoded message and metadata associated with the message, and storing the encoded block in the data storage system. Example methods and apparatus may employ Reed Solomon erasure codes or Fountain erasure codes. Example methods and apparatus may display to a user the storage capacity and durability of the data storage system.

Abstract: Methods and apparatus associated with data cold storage are described. Example apparatus include an array of data storage devices arranged in rows and columns. Columns of the array are orthogonal to rows. A row has an associated row-centric power supply, and a column has an associated column-centric local electronics module (LEM) that controls a data storage device in the column independently of other data storage devices in the array. Example apparatus include logics that control a power mode of a data storage device independently of other data storage devices in the array, that control a power mode of an LEM, that adaptively regulate the level of data stored in a buffer, and that determine whether a data object will be stored in the buffer or stored on a data storage device in the array, based on the probability the data object will be accessed within a threshold period of time.

Abstract: Methods and apparatus associated with storing data in high or low energy zones are described. Example apparatus include a data storage system (DSS) that protects a message using an erasure code (EC). A location in the DSS may have an energy efficiency rating or a latency. Example apparatus include circuits that produce EC encoded data that has a likelihood of use, that select a location to store the EC encoded data in the DSS based on the energy efficiency rating, the latency, or the likelihood of use, that store the EC encoded data in the location, and that compute an order of retrieval for EC encoded data stored in the location. The order of retrieval may be based on the energy efficiency rating or the latency. The EC encoded data may also have a priority based on the number of erasures for which the EC corrects.

Abstract: Methods, apparatus, and other embodiments associated with adaptive use of erasure codes for distributed data storage systems are described. One example method includes accessing a message, where the message has a message size, selecting an encoding strategy as a function of the message size, data storage device failure statistics, data storage device wear periods, data storage space constraints, or overhead constraints, and where the encoding strategy includes an erasure code approach, generating an encoded message using the encoding strategy, generating an encoded block, where the encoded block includes the encoded message and metadata associated with the message, and storing the encoded block in the data storage system. Example methods and apparatus may employ Reed Solomon erasure codes or Fountain erasure codes. Example methods and apparatus may display to a user the storage capacity and durability of the data storage system.

Abstract: Methods and apparatus associated with storing data in high or low energy zones are described. Example apparatus include a data storage system (DSS) that protects a message using an erasure code (EC). A location in the DSS may have an energy efficiency rating or a latency. Example apparatus include logics that produce an EC that has a likelihood of use, that select a location to store the EC in the DSS based on the energy efficiency rating, the latency, or the likelihood of use, that store the EC in the location, and that compute an order of retrieval for an EC stored in the location. The order of retrieval may be based on the energy efficiency rating or the latency. The EC may also have a priority based on the number of erasures for which the EC corrects.

Abstract: Methods and apparatus associated with storing data in high or low energy zones are described. Example apparatus include a data storage system (DSS) that protects a message using an erasure code (EC). A location in the DSS may have an energy efficiency rating or a latency. Example apparatus include circuits that produce EC encoded data that has a likelihood of use, that select a location to store the EC encoded data in the DSS based on the energy efficiency rating, the latency, or the likelihood of use, that store the EC encoded data in the location, and that compute an order of retrieval for EC encoded data stored in the location. The order of retrieval may be based on the energy efficiency rating or the latency. The EC encoded data may also have a priority based on the number of erasures for which the EC corrects.

Abstract: Methods and apparatus associated with data cold storage are described. Example apparatus include an array of data storage devices arranged in rows and columns. Columns of the array are orthogonal to rows. A row has an associated row-centric power supply, and a column has an associated column-centric local electronics module (LEM) that controls a data storage device in the column independently of other data storage devices in the array. Example apparatus include logics that control a power mode of a data storage device independently of other data storage devices in the array, that control a power mode of an LEM, that adaptively regulate the level of data stored in a buffer, and that determine whether a data object will be stored in the buffer or stored on a data storage device in the array, based on the probability the data object will be accessed within a threshold period of time.