Abstract: A disc cassette includes a curved portion configured to hold multiple discs. A platform portion abuts the curved portion. A movable bale is configured to maintain discs securely in the disc cassette.

Abstract: Aspects of the present invention include a system, method, and computer program product for skewing expected wearout times of memory devices in an array are provided according to some embodiments of the present invention. In general, the method includes determining or receiving an amount of spare space to provide in an array of memory devices, allocating the spare space non-uniformly to the memory devices in the array, and skewing expected wearout times of the memory devices by controlling writing of data to the array according to the allocation of the spare space.

Abstract: Embodiments relate to correcting erasures in a storage array. An aspect includes dividing data into a plurality of stripes for storage in a storage array comprising a plurality of storage locations, each stripe comprising M rows and N columns, each of the M rows including a number r of row parities, wherein r is greater than zero. Another aspect includes dividing each stripe into two or more column sets, each column set comprising a respective set of one or more columns of the stripe. Another aspect includes adding a respective first responder parity to each column set, wherein each first responder parity gives parity information for only the two or more columns in the first responder parity's respective column set.

Abstract: Embodiments relate to correcting erasures in a storage array. An aspect includes dividing data into a plurality of stripes for storage in a storage array comprising a plurality of storage locations, each stripe comprising M rows and N columns, each of the M rows including a number r of row parities, wherein r is greater than zero. Another aspect includes dividing each stripe into two or more column sets, each column set comprising a respective set of one or more columns of the stripe. Another aspect includes adding a respective first responder parity to each column set, wherein each first responder parity gives parity information for only the two or more columns in the first responder parity's respective column set. Yet another aspect includes, based on an isolated erasure in a column set, correcting the isolated erasure by reading data from only storage locations corresponding to the column set in which the isolated erasure occurred using the first responder parity of the column set.

Abstract: A computer-implemented method includes receiving a request for data; determining whether the data is stored in a linear storage media tier and/or in a second storage tier having higher performance than the linear storage media tier. The linear storage media tier includes: reels having linear media thereon, a rest area for storing the reels when not in use, linear media drive(s) configured for reading and/or writing the linear media, and mobile robot(s) for transporting the linear storage media between the rest area and the linear media drive(s). The method also includes instructing the mobile robot to transport one of the reels having the data thereon to one of the linear media drives in the linear storage media tier when the data is stored in the linear storage media tier; receiving the data from the one of the linear media drives; and sending the data.

Abstract: Aspects of the present invention include a system, method, and computer program product for skewing expected wearout times of memory devices in an array are provided according to some embodiments of the present invention. In general, the method includes determining or receiving an amount of spare space to provide in an array of memory devices, allocating the spare space non-uniformly to the memory devices in the array, and skewing expected wearout times of the memory devices by controlling writing of data to the array according to the allocation of the spare space.

Abstract: Aspects of the present invention include a system, method, and computer program product for skewing expected wearout times of memory devices in an array are provided according to some embodiments of the present invention. In general, the method includes determining or receiving an amount of spare space to provide in an array of memory devices, allocating the spare space non-uniformly to the memory devices in the array, and skewing expected wearout times of the memory devices by controlling writing of data to the array according to the allocation of the spare space.

Abstract: A data storage structure, comprising: a plurality of storage units, each comprising: a storage media; and a library executive configured to manage the storage media. The structure further comprises a buffer connected to a controller, the controller comprising: a host interface configured to receive the instruction from the host machine; an object aggregator configured to combine the plurality of data objects into a data segment; a persistent write buffer configured to store the data segment; a persistent map configured to identify a location of each of the plurality of objects in the data segment; an erasure coder configured to encode the data segment into an erasure code; a destager configured to transfer the data segment from the persistent write buffer to the storage media in a given storage unit; and a library controller configured to communicate with the library executive in the given storage unit.

Abstract: An apparatus includes one or more disc media cassettes configured to store multiple disc-based media. Multiple disc drives are configured to read and write data to the multiple disc-based media. A robotic delivery device is configured to transport a selected disc-based media to and from at least one disc drive of the multiple disc drives, and to transport the selected disc-based media directly to a spindle on the at least one disc drive.

Abstract: An optical disc drive includes a spindle connected to an optical assembly. A disc clamp device is configured to hold an optical disc on the spindle. A contiguous opening on at least two adjacent sides in a plane of a disc mount position intersect at a common corner of the optical disc drive.

Abstract: A disc cassette includes a curved portion configured to hold multiple discs. A platform portion abuts the curved portion. A movable bale is configured to maintain discs securely in the disc cassette.

Abstract: An apparatus includes one or more disc media cassettes configured to store multiple disc-based media. Multiple disc drives are configured to read and write data to the multiple disc-based media. A robotic delivery device is configured to transport a selected disc-based media to and from at least one disc drive of the multiple disc drives, and to transport the selected disc-based media directly to a spindle on the at least one disc drive.

Abstract: One embodiment provides a method for reclaiming free space. The method comprises selecting a first blob for reclamation from a first data center; sending a first message to a second data center indicating the first blob is to be reclaimed; sending a second message to the second data center after reclaiming the first blob; receiving a global reclamation complete message from the second data center; reading at least one data set from the first blob; and storing in a write buffer the at least one data set for encoding into a erasure code group in an alternative blob in the first data center. Further, upon receipt of the global reclamation message from the second data center, indicating the first blob is free in the map in the first data center. In one embodiment, selecting the first blob is based on the map indicating free space in the first data center.

Abstract: An apparatus includes a first jaw device, a second jaw device, and a disc sensor configured to sense presence of a storage disc between the first jaw device and the second jaw device. The first jaw device and the second jaw device form a gripper device configured to clamp a particular portion of a storage disc including an arc segment along an outer edge of adjacent surfaces of the storage disc.

Abstract: One embodiment provides a method for storing data in a data storage system. The method comprises copying a data set into a buffer in a data storage center in response to receiving a write command for the data set; updating a content map; and sending to a second data storage center a parity write command for the data set. The method continues with copying the data set into a buffer in the second data storage center; updating a second content map; and sending to the first data storage center an acknowledgement indicating the parity write command is complete. Then in response to receiving the acknowledgement, updating the first content map; moving the data set to a storage unit in first data storage center; and acknowledging the data set is protected. Finally, releasing the data set from the first buffer; and updating the first map content.

Abstract: A method for hierarchical correction coding includes converting data for a storage system into w storage device arrays, each storage device array including n storage devices, and each storage device divided into m sectors or pages. The n storage devices are grouped into l groups of t storage devices each. Erasures in the w storage device arrays are corrected based on protecting each row and column in each m×n array by an erasure-correcting code. Each group of t storage devices contains extra parities to correct extra erasures in addition to erasures corrected by vertical parities in each m×t subarray, and w, n, m, l and t are positive integers.

Abstract: A method for distributed coding in a storage array is presented. The method includes dividing data into multiple stripes for storage in a storage array including storage devices with a topology of a hypercube of a dimension t?3. The storage devices in same hypercubes of dimension t?1 including the hypercube of a dimension t have even parity. Global parities are added to the hypercube such that a minimum distance of a code is enhanced.

Abstract: An apparatus includes a motor configured to drive a driving element within a housing. A caliper is connected to the housing and configured to force a first jaw device toward a second jaw device based on movement of the driving element. A disc sensor is configured to sense presence of a storage disc and to limit insertion travel of a storage disc between the first jaw device and the second jaw device. The first jaw device and the second jaw device form a gripper device configured to clamp a particular portion of a storage disc.

Abstract: Bitmap compression for fast searches and updates is provided. Compressing a bitmap includes receiving a bitmap to compress, and reading the bitmap to determine a value of a bit location for all bits in the bitmap. In one embodiment, a compressed bitmap is created by encoding a variable number of bytes to represent a distance between adjacent 1s in the uncompressed bitmap. In another embodiment, a compressed bitmap is created by representing a distance between adjacent 1s in the uncompressed bitmap using a plurality of bits, and encoding a marker word to indicate the number of bits used to represent the distance.

Abstract: A computer-implemented method is provided for increasing the failure tolerance of an array of storage elements in a storage system. The computer-implemented method includes configuring an array to include a plurality of storage elements in n>1 sets of storage elements. The computer-implemented method also includes configuring an erasure-correcting code such that at least one column of the storage elements of the array stores row parity information, and at least one row of the storage elements of the array stores column parity information. Still yet, the computer-implemented method includes, subsequent to a failure of one of the storage elements storing data, selecting a recipient storage element from the array, and rebuilding at least a portion of the data onto the recipient storage element by performing a parity exchange operation that retains a failure tolerance of the set of storage elements containing the failed storage element.