Progressive parity
AssigneeSpectra Logic Corporation
InventorsDavid Lee Trachy, Joshua Daniel Carter
Life of this patent
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Abstract
A magazine-based data storage library is described that essentially provides a first tape cartridge adapted to retain first data and first metadata, a second tape cartridge adapted to retain second data and second metadata, a random access storage memory, such as a hard disk drive, whereon parity of the first data and the second data along with the first metadata and second metadata is retained. It is not required that the first data and the second data be written in parallel. The parity data on the random access storage memory is transferred to a parity tape, which can be used to reconstruct any data lost from either the first tape cartridge or the second tape cartridge.
Claims15
A method comprising:
- providing a data storage system with a data storage medium, a second data storage medium, a parity data storage medium, a first data transfer device, and a dedicated random storage access memory device;
- loading the first data storage medium into the first data transfer device;
- storing first data and first metadata corresponding to the first data to the first data storage medium via the first data transfer device;
- storing the first data to the dedicated random storage access memory device;
- disengaging the first data storage medium from the first data transfer device;
- loading the second data storage medium into the first data transfer device;
- storing second data and second metadata corresponding to the second data to the second data storage medium via the first data transfer device;
- after said storing first data step, generating parity data of the first data and the second data to the dedicated random access memory device.
A method for constructing parity in a tape cartridge set, the method comprising:
- providing a tape library with a plurality of tape cartridges including cartridge-x and cartridge-y, a first tape drive, a second tape drive, and dedicated random access storage capability;
- loading the cartridge-x into the first tape drive;
- storing a sequence of x-bits to cartridge-x via the first tape drive;
- storing a coinciding sequence of the x-bits to the dedicated random storage access storage capability while storing the sequence of x-bits to cartridge-x;
- disengaging the cartridge-x from the first tape drive;
- disposing the cartridge-x in a holding receptacle;
- loading the cartridge-y into the second tape drive before disengaging the cartridge-x from the first tape drive;
- storing a sequence of y-bits to cartridge-y via the second tape drive before the x-bits are finished being stored to the cartridge-x;
- overwriting the sequence of the x-bits to the dedicated random storage access storage capability with a parity of the y-bits and the x-bits to the dedicated random access storage capability, while storing the sequence of y-bits to cartridge-y.
Dependencies are inferred from the claim text.