Abstract: According to one embodiment, a computer-implemented method includes receiving an object to be stored within a storage library, computing a hash value, utilizing the object, determining a storage location within the storage library to store the hash value, and sending the hash value to the storage location and neighbor locations of the storage location within the storage library.

Abstract: One embodiment provides a method comprising maintaining, on a storage unit, mapping data between a first set of logical addresses (e.g., logical block addresses or LBAs) viewed by a host and a first set of physical addresses (e.g., physical block addresses or PBAs) and a second set of physical addresses of the storage unit. A first logical address (e.g., LBA) of the first set of logical addresses corresponds to a first physical address (e.g., PBA) of the first set of physical addresses that maintains current data for the first logical address. The first logical address further corresponds to a second physical address (e.g., PBA) of the second set of physical addresses that maintains prior data for the first logical address. The method further comprises receiving, at the storage unit, a command from the host to perform a multi-device operation involving the first logical address. The operation is performed atomically.

Abstract: According to one embodiment, a computer-implemented method includes receiving an object to be stored within a storage library, computing a hash value, utilizing the object, determining a storage location within the storage library to store the hash value, and sending the hash value to the storage location and neighbor locations of the storage location within the storage library.

Abstract: A controller including an object aggregator process that combines multiple data objects into a data segment, and transfers the data segment with reduced location metadata to storage media of at least one of multiple storage units. An erasure coder process generates code to encode the data segment into an erasure code that protects against concurrent data loss in the multiple storage units based on data reconstruction using a first responder, a second responder and a last responder.

Abstract: One embodiment provides a method comprising maintaining, on a storage unit, mapping data between a first set of logical addresses (e.g., logical block addresses or LBAs) viewed by a host and a first set of physical addresses (e.g., physical block addresses or PBAs) and a second set of physical addresses of the storage unit. A first logical address (e.g., LBA) of the first set of logical addresses corresponds to a first physical address (e.g., PBA) of the first set of physical addresses that maintains current data for the first logical address. The first logical address further corresponds to a second physical address (e.g., PBA) of the second set of physical addresses that maintains prior data for the first logical address. The method further comprises receiving, at the storage unit, a command from the host to perform a multi-device operation involving the first logical address. The operation is performed atomically.

Abstract: A controller including an object aggregator process that combines multiple data objects into a data segment, and transfers the data segment with reduced location metadata to storage media of at least one of multiple storage units. An erasure coder process generates code to encode the data segment into an erasure code that protects against concurrent data loss in the multiple storage units based on data reconstruction using a first responder, a second responder and a last responder.

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: 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: Embodiments of the invention relate to receiving a write request that includes a write data and an address of a target block in tertiary storage. In response to the write request, a write-miss is detected at a cache located in persistent storage. Based on detecting the write-miss, the write data and associated metadata are written to a fast write storage location and the write request is marked as complete. In addition, the target block is retrieved from the address in the tertiary storage and stored in the cache. Contents of the fast write storage location are merged with the contents of the target block in the cache.

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: Embodiments relate to a computer system for storing data on a time multiplexed redundant array of independent tapes. An aspect includes a memory device that buffers data received by the computer system to be written to a set of tape data storage devices. The data is written to the set of tape data storage devices in blocks that form parity stripes across the set of tape data storage device. Aspects further includes a tape drive that writes data to one of the set of tape data storage devices at a time in a tape-sequential manner and a processor that computes a parity value for each of the parity stripes. The tape drive writes the parity values for each of the parity stripes to a last subset of tapes of the set of tape data storage devices.

Abstract: Embodiments of the invention provide parity logs for raid systems with variable-capacity media. In one embodiment, a system includes a first set of data storage media devices having variable capacity. The storage devices include a data portion of a parity data set for storing write data being striped to the first. The system further includes a second set of data storage media devices having variable capacity. The second set includes a linear address space of blocks for storing a parity portion of the parity data set. The linear address space is written in a log form. The first and second sets comprise at least one array in a RAID configuration. The system writes the parity portion of the parity data set to the second set, which enables each storage device among the first set to be written to full capacity.

Abstract: Embodiments of the invention relate to receiving a write request that includes a write data and an address of a target block in tertiary storage. In response to the write request, a write-miss is detected at a cache located in persistent storage. Based on detecting the write-miss, the write data and associated metadata are written to a fast write storage location and the write request is marked as complete. In addition, the target block is retrieved from the address in the tertiary storage and stored in the cache. Contents of the fast write storage location are merged with the contents of the target block in the cache.

Abstract: Embodiments of the invention relate to cache management of sequential write storage. Cache states of cache blocks in cache storage are tracked. The tracking incudes creating a migration candidate list that organizes the cache blocks into virtual volumes. Based on determining that a cache migration threshold has been reached, at least a subset of the cache blocks are selected from the migration candidate list for migration. The selected cache blocks are ordered into a sequential order based on the migration candidate list. At least a subset of the selected cache blocks are migrated in the sequential order, the migrating including writing contents of the selected cache blocks to the sequential write storage.

Abstract: Embodiments of the invention provide parity logs for raid systems with variable-capacity media. In one embodiment, a system includes a first set of data storage media devices having variable capacity. The storage devices include a data portion of a parity data set for storing write data being striped to the first. The system further includes a second set of data storage media devices having variable capacity. The second set includes a linear address space of blocks for storing a parity portion of the parity data set. The linear address space is written in a log form. The first and second sets comprise at least one array in a RAID configuration. The system writes the parity portion of the parity data set to the second set, which enables each storage device among the first set to be written to full capacity.

Abstract: Embodiments relate to a computer system for storing data on a time multiplexed redundant array of independent tapes. An aspect includes a memory device that buffers data received by the computer system to be written to a set of tape data storage devices. The data is written to the set of tape data storage devices in blocks that form parity stripes across the set of tape data storage device. Aspects further includes a tape drive that writes data to one of the set of tape data storage devices at a time in a tape-sequential manner and a processor that computes a parity value for each of the parity stripes. The tape drive writes the parity values for each of the parity stripes to a last subset of tapes of the set of tape data storage devices.

Abstract: Embodiments of the invention relate to cache management of sequential write storage. Cache states of cache blocks in cache storage are tracked. The tracking incudes creating a migration candidate list that organizes the cache blocks into virtual volumes. Based on determining that a cache migration threshold has been reached, at least a subset of the cache blocks are selected from the migration candidate list for migration. The selected cache blocks are ordered into a sequential order based on the migration candidate list. At least a subset of the selected cache blocks are migrated in the sequential order, the migrating including writing contents of the selected cache blocks to the sequential write storage.

Abstract: A system includes a linear storage media tier; a second storage tier having higher performance than the linear storage media tier; a data controller for moving data between the tiers; and a host interface responsive to disk and/or network storage commands. The linear storage media tier includes: a rest area for storing reels having linear media thereon, at least one linear media drive configured for reading and/or writing the linear media, and at least one robot for transporting the linear storage media between the rest area and the at least one linear media drive. The robot moves along a first surface via contact with the surface. A system according to another embodiment includes a linear storage media tier characterized by having a read access time to any block of data stored on any reel in the rest area in less than 10 seconds.

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: A system includes a linear storage media tier; a second storage tier having higher performance than the linear storage media tier; a data controller for moving data between the tiers; and a host interface responsive to disk and/or network storage commands. The linear storage media tier includes: a rest area for storing reels having linear media thereon, at least one linear media drive configured for reading and/or writing the linear media, and at least one robot for transporting the linear storage media between the rest area and the at least one linear media drive. The robot moves along a first surface via contact with the surface. A system according to another embodiment includes a linear storage media tier characterized by having a read access time to any block of data stored on any reel in the rest area in less than 10 seconds.