Abstract:
A method for protecting redundancy of data recorded through multiple layers of a recording medium is provided to reduce a danger of inaccessibility or a loss of the data when the data on at least one layer is not decoded and to improve creditability of the recording medium and stability of the recorded data. A method for protecting redundancy of data recorded through multiple layers of a recording medium includes a step of receiving a data stream, a step of encoding each data bit to the predetermined number of expression bits, a step of recording a first expression bit at a first layer, recording a second expression bit at a second layer, and recording a remaining expression bit at the other layers of the recording medium, a step of receiving a request for decoding the data recorded from the recording medium, a step of reading back the plural expression bits from the recording medium, and a step of decoding the plural expression bits to an original data bit.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for selecting an overlap exclusion protocol for a data storage library including a plurality of data storage devices that is constituted as RAID array.SOLUTION: The method sets a regular overlap exclusion protocol, an overlap exclusion protocol for RAID failure, and an overlap exclusion protocol for failures of a plurality of storage devices. The method receives host data including a plurality of interleaved data blocks. When a system operates without any storage device failure, the method processes the host data by using the regular overlap exclusion protocol. When the system is operating with a storage device failure, the method processes the host data by using the overlap exclusion protocol for the RAID failure. When the system is operating with failures occurring in the plurality of storage devices, the method processes the host data by using the overlap exclusion protocol for the failures of the plurality of storage devices.
Abstract:
A method to allocate resources in a data storage library comprising a plurality of data storage devices configured as a RAID array, by establishing a normal operation resource allocation, a RAID failure resource allocation, and a multiple storage device failure resource allocation. The method receives host I/O requests, and enqueues those host I/O requests. If the system is operating without any storage device failures, then the method processes host I/O requests using the normal operation resource allocation. If the system is operating with a storage device failure, then the method processes host I/O requests using the RAID failure resource allocation. If the system is operating with multiple storage device failures, then the method processes host I/O requests using the multiple storage device failure resource allocation.
Abstract:
An apparatus and method are disclosed to generate convolution encoded data. The method supplies a convolution encoder. The method receives original data and generates convolution encoded original data. The method receives revised data. The method generates an XOR data stream by Exclusive OR'ing the original data with the revised data, forms a convolution encoded XOR data stream using the convolution encoder, and Exclusive ORs the convolution encoded XOR data stream with the convolution encoded original data to generate convolution-encoded revised data.
Abstract:
A method to select a deduplication protocol for a data storage library comprising a plurality of data storage devices configured as a RAID array, establishes a normal deduplication protocol, a RAID failure deduplication protocol, and a multiple storage device failure deduplication protocol. The method receives host data comprising a plurality of interleaved data blocks. If the system is operating without any storage device failures, then the method processes the host data using the normal deduplication protocol. If the system is operating with a storage device failure, then the method processes the host data using the RAID failure deduplication protocol. If the system is operating with multiple storage device failures, then the method processes the host data using the multiple storage device failure deduplication protocol.
Abstract:
Data for storage by holographic data storage is arranged in an intermedia te data storage as data segments which are replicas of holographic storage s egments. Files of data are aggregated into the data segments, and a destagin g control determines the destaging of the data segments to the holographic d ata storage in accordance with a plurality of policies, such as whether a se gment is full, a time threshold has been reached, or whether a threshold num ber of segments are "open". The intermediate data storage may be arranged in to a number of partitions at least equal to the number of sources having inp ut to the data destaging system, the partitions comprising integral multiple s of the data segments.