A system determines the data stored on a piece of magnetic media by obtaining an image that represents the magnetic state of the piece of magnetic media using a magneto-optic image sensor. In an example, the image sensor is connected to a mechanism that moves over the piece of magnetic media, and the system takes a plurality of images which are stitched together into a composite image of the state of the piece of magnetic media. The system analyzes the image to identify regions that contain data, extracts the encoded data from the regions. The encoded data is decoded in accordance with an encoding scheme used by the piece of magnetic media. In some examples, a file structure is applied to the data and data files are recovered from the image. In various examples, the piece of magnetic media can be hard disk media, floppy disk media, or magnetic tape.

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.

A system determines the data stored on a piece of magnetic media by obtaining an image that represents the magnetic state of the piece of magnetic media using a magneto-optic image sensor. In an example, the image sensor is connected to a mechanism that moves over the piece of magnetic media, and the system takes a plurality of images which are stitched together into a composite image of the state of the piece of magnetic media. The system analyzes the image to identify regions that contain data, extracts the encoded data from the regions. The encoded data is decoded in accordance with an encoding scheme used by the piece of magnetic media. In some examples, a file structure is applied to the data and data files are recovered from the image. In various examples, the piece of magnetic media can be hard disk media, floppy disk media, or magnetic tape.

In one aspect of the present invention, an apparatus includes a head configured to write data to a tape, and a hardware controller coupled to the head. The controller is configured to cause the apparatus to copy a second data area on the tape as a third data area, the second data area corresponding to data in a first data area that has changed. The controller is also configured to cause the apparatus to store, on the tape, index information for identifying the third data area, and copy the first data area to the tape as a fourth data area separate from the third data area. The controller is also configured to cause the apparatus to store, on the tape, index information for identifying the fourth data area.

A non-transitory computer readable storage medium includes a tape having a plurality of partitions configured for storing data, and a plurality of read-only partition identifiers, each read-only partition identifier associated with one of the plurality of partitions and readable by a tape drive having a processor and memory for writing and reading tape data. Each read-only partition identifier selectively designates a corresponding one of the partitions as read-only to prevent data from being written to the designated read-only partition by the tape drive.

Described are techniques for a tape unmounting protocol. The techniques include selecting a tape for unmounting from a plurality of tape drives, where the tape for unmounting includes a remaining capacity below a first threshold and a number of migrated files below a second threshold. The techniques further include unmounting the tape for unmounting from a tape drive.

Described are techniques for a tape unmounting protocol. The techniques include selecting a tape for unmounting from a plurality of tape drives, where the tape for unmounting includes a remaining capacity below a first threshold and a number of migrated files below a second threshold. The techniques further include unmounting the tape for unmounting from a tape drive.

A non-transitory computer readable storage medium includes a tape having a plurality of partitions configured for storing data, and a plurality of read-only partition identifiers, each read-only partition identifier associated with one of the plurality of partitions and readable by a tape drive having a processor and memory for writing and reading tape data. Each read-only partition identifier selectively designates a corresponding one of the partitions as read-only to prevent data from being written to the designated read-only partition by the tape drive.

A method and system for reducing storage requirements and speeding up storage operations by reducing the storage of redundant data includes receiving a request that identifies one or more data objects to which to apply a storage operation. For each data object, the storage system determines if the data object contains data that matches another data object to which the storage operation was previously applied. If the data objects do not match, then the storage system performs the storage operation in a usual manner. However, if the data objects do match, then the storage system may avoid performing the storage operation.

A method and system for reducing storage requirements and speeding up storage operations by reducing the storage of redundant data includes receiving a request that identifies one or more data objects to which to apply a storage operation. For each data object, the storage system determines if the data object contains data that matches another data object to which the storage operation was previously applied. If the data objects do not match, then the storage system performs the storage operation in a usual manner. However, if the data objects do match, then the storage system may avoid performing the storage operation.