Abstract: Data deduplication for data storage tapes includes intercepting tape control commands for a single data storage tape. The intercepted tape control commands are modified for adding processing logic and parameters for placement of deduplicated file data on the single data storage tape. Deduplication metadata is written to a metadata portion of the single data storage tape. The deduplicated file data is written to a data portion of the single data storage tape based on the placement to increase read throughput for a deduplicated set of individual files and to reduce an average number of per-file gaps on the single data storage tape without re-duplicating deduplicated data for meeting optimization of individual file accesses.

Abstract: In one embodiment, a data storage system includes a tape drive configured to: write a plurality of files to a first partition of a magnetic recording tape; and write an index to a second partition of the magnetic recording tape, the index including information about locations of data of the plurality of files in the first partition of the magnetic recording tape. In another embodiment, a magnetic recording tape includes: a plurality of files to written to a first partition of the magnetic recording tape using a tape drive; and an index written to a second partition of the magnetic recording tape using the tape drive, the index including information about locations of data of the plurality of files in the first partition of the magnetic recording tape.

Abstract: Embodiments relate to a system with multiple erasure codes, and selecting and encoding for a write file with one of the codes to mitigate costs associated with storage recovery. The codes include a fast recovery code for frequently accessed data and a higher storage efficiency code for less frequently accessed data. State data is tracked to ascertain frequency of access to the file. One of the erasure codes is dynamically selected based on the tracked data, with the focus of the code select to lower recovery costs, and the data is encoded with the selected erasure code. Accordingly, the original coding of the write file is subject to change based on the tracked state data.

Abstract: Various embodiments relate to providing dynamic absolute-path symbolic links. According to one embodiment, indication of a symbolic link is received, which references a target, the indication including an absolute path of the target that includes a target mount point and a name of the target. A current mount point of the target is identified, and a verification is made that the target mount point is identical to the current mount point. When the target mount point is identical to the current mount point, a string length of the current mount point is determined, and an in-memory record of the symbolic link is created. The in-memory record includes the string length of the current mount point associated with the symbolic link.

Abstract: Data deduplication for data storage tapes includes intercepting tape control commands for a single data storage tape. The intercepted tape control commands are modified for adding processing logic and parameters for placement of deduplicated file data on the single data storage tape. Deduplication metadata is written to a metadata portion of the single data storage tape. The deduplicated file data is written to a data portion of the single data storage tape based on the placement to increase read throughput for a deduplicated set of individual files and to reduce an average number of per-file gaps on the single data storage tape without re-duplicating deduplicated data for meeting optimization of individual file accesses.

Abstract: Data deduplication for data storage tapes includes intercepting tape control commands for a single data storage tape. The intercepted tape control commands are modified by adding processing logic and parameters for placement of deduplicated file data on the single data storage tape. Deduplication metadata is written to a metadata portion of the single data storage tape. The deduplicated file data is written to a data portion of the single data storage tape based on the placement to increase read throughput for a deduplicated set of individual files and to reduce an average number of per-file gaps on the single data storage tape without re-duplicating deduplicated data for meeting optimization of individual file accesses.

Abstract: Embodiments relate to dynamically selecting an erasure code. State data is tracked to ascertain frequency of file access. One of at least two erasure codes are selected based on the tracked state data in order to lower data recovery cost. The erasure code may be selected as either a product code or a local reconstruction code. Each erasure code includes a mode that is either a fast code or a compact code. The fast code features a low recovery cost and the compact code features a low storage overhead for less frequently accessed data. Data is encoded with one of the selected erasure codes and one of the modes of the selected erasure code. Data blocks are dynamically converted between the fast and compact codes of the selected erasure code responsive to a workload change.

Abstract: Various embodiments relate to providing dynamic absolute-path symbolic links. According to one embodiment, indication of a symbolic link is received, which references a target, the indication including an absolute path of the target that includes a target mount point and a name of the target. A current mount point of the target is identified, and a verification is made that the target mount point is identical to the current mount point. When the target mount point is identical to the current mount point, a string length of the current mount point is determined, and an in-memory record of the symbolic link is created. The in-memory record includes the string length of the current mount point associated with the symbolic link.

Abstract: Embodiments of the invention relate to providing dynamic absolute-path symbolic links. According to one embodiment, indication of a symbolic link is received, which references a target, the indication including an absolute path of the target that includes a target mount point and a name of the target. A current mount point of the target is identified, and a verification is made that the target mount point is identical to the current mount point. When the target mount point is identical to the current mount point, a string length of the current mount point is determined, and an in-memory record of the symbolic link is created. The in-memory record includes the string length of the current mount point associated with the symbolic link.

Abstract: Embodiments relate to dynamically selecting an erasure code. State data is tracked to ascertain frequency of file access. One of at least two erasure codes are selected based on the tracked state data in order to lower data recovery cost. The erasure code may be selected as either a product code or a local reconstruction code. Each erasure code includes a mode that is either a fast code or a compact code. The fast code features a low recovery cost and the compact code features a low storage overhead for less frequently accessed data. Data is encoded with one of the selected erasure codes and one of the modes of the selected erasure code. Data blocks are dynamically converted between the fast and compact codes of the selected erasure code responsive to a workload change.

Abstract: Embodiments relate to a system with multiple erasure codes, and selecting and encoding for a write file with one of the codes to mitigate costs associated with storage recovery. The codes include a fast recovery code for frequently accessed data and a higher storage efficiency code for less frequently accessed data. State data is tracked to ascertain frequency of access to the file. One of the erasure codes is dynamically selected based on the tracked data, with the focus of the code select to lower recovery costs, and the data is encoded with the selected erasure code. Accordingly, the original coding of the write file is subject to change based on the tracked state data.

Abstract: In one embodiment, a data storage system includes a tape drive configured to: write a plurality of files to a first partition of a magnetic recording tape; and write an index to a second partition of the magnetic recording tape, the index including information about locations of data of the plurality of files in the first partition of the magnetic recording tape. In another embodiment, a magnetic recording tape includes: a plurality of files to written to a first partition of the magnetic recording tape using a tape drive; and an index written to a second partition of the magnetic recording tape using the tape drive, the index including information about locations of data of the plurality of files in the first partition of the magnetic recording tape.

Abstract: In one embodiment, a computer program product for writing data to a magnetic recording tape includes a computer readable storage medium having computer readable program code embodied therewith. The computer readable program code includes: computer readable program code configured to cause a tape drive to: write a plurality of files to a first partition of a magnetic recording tape; and write an index to a second partition of the magnetic recording tape. The index includes information about locations of data of the plurality of files in the first partition of the magnetic recording tape. A longitudinal buffering band is present between the first and second partitions; and is configured to isolate writing in the first partition from overwriting neighboring tracks in the second partition. The longitudinal buffering band comprises an entirety of at least one full wrap of the magnetic recording tape.

Abstract: Embodiments relate to a system with multiple erasure codes, and selecting and encoding for a write file with one of the codes to mitigate costs associated with storage recovery. The codes include a fast recovery code for frequently accessed data and a higher storage efficiency code for less frequently accessed data. State data is tracked to ascertain frequency of access to the file. One of the erasure codes is dynamically selected based on the tracked data, with the focus of the code select to lower recovery costs, and the data is encoded with the selected erasure code. Accordingly, the original coding of the write file is subject to change based on the tracked state data.

Abstract: In one embodiment, a method for writing data to a magnetic recording tape includes writing a plurality of files to a first partition of a magnetic recording tape using a tape drive, and writing an index to a second partition of the magnetic recording tape using the tape drive, the index including information about locations of data of the plurality of files in the first partition of the magnetic recording tape.

Abstract: Embodiments of the invention relate to a para-virtual I/O system. A state of a filesystem associated with a para-virtual I/O system is updated, which includes performing semantic journaling in support of the update. The semantic journaling includes writing one or more data blocks and logging metadata updates to a journal. A cache flush request is received and classified based on semantic information of the system. The classification provides an order of commands for processing the received request. The classification is converted into an order of committed writes, and the order of committed writes is processed. The processing includes enforcing the order of committed writes to provide a consistent virtual disk image.

Abstract: Embodiments relate to a system with multiple erasure codes, and selecting and encoding for a write file with one of the codes to mitigate costs associated with storage recovery. The codes include a fast recovery code for frequently accessed data and a higher storage efficiency code for less frequently accessed data. State data is tracked to ascertain frequency of access to the file. One of the erasure codes is dynamically selected based on the tracked data, with the focus of the code select to lower recovery costs, and the data is encoded with the selected erasure code. Accordingly, the original coding of the write file is subject to change based on the tracked state data.

Abstract: Embodiments of the invention relate to a para-virtual I/O system. A consistent para-virtual I.O system architecture is provided with a new virtual disk interface and a semantic journaling mechanism. The virtual disk interface is extended with two primitives for flushing and ordering I/O, both of the primitives being exported to para-virtual I/O drivers in a guest operating system. The ordering primitive guarantees ordering of preceeding writes, and the flushing primitive enforces order and durability. The guest drivers selectively uses both of these primitives based on semantics of the data being persisted from the para-virtual cache hierarchy to physical disk. The order of committed writes is enforced in order to enable a consistent start recovered after a crash.

Abstract: Embodiments of the invention relate to a para-virtual I/O system. A consistent para-virtual I.O system architecture is provided with a new virtual disk interface and a semantic journaling mechanism. The virtual disk interface is extended with two primitives for flushing and ordering I/O, both of the primitives being exported to para-virtual I/O drivers in a guest operating system. The ordering primitive guarantees ordering of preceeding writes, and the flushing primitive enforces order and durability. The guest drivers selectively uses both of these primitives based on semantics of the data being persisted from the para-virtual cache hierarchy to physical disk. The order of committed writes is enforced in order to enable a consistent start recovered after a crash.

Abstract: A system according to one embodiment includes a tape cartridge, the tape cartridge comprising: a housing; a magnetic recording tape in the housing; and a non-tape nonvolatile memory coupled to the housing, the nonvolatile memory being for storing therein an index comprising file system information for a plurality of files stored on the magnetic recording tape. A method for storing data on a tape cartridge according to one embodiment includes writing a plurality of files to a magnetic recording tape of a tape cartridge; and writing an index to a non-tape nonvolatile memory of the tape cartridge, the index including information about locations of data of the plurality of files on the magnetic recording tape.