Dual redundant data storage format and method
AssigneeSeagate Technology LLC
InventorsClark Edward Lubbers, David Peter DeCenzo
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Abstract
Disclosed is a data storage architecture that provides data regeneration following the failure of two storage domains and that provides conversion for RAID-6 to RAID-5 or RAID-0 without moving or copying any data. A storage grid comprising at least eight domains and twelve rows contains user data in a first contiguous portion and may contain row parity data in a second continuous portion and may contain vertical parity data in a third contiguous portion. In one embodiment data is arranged in row and vertical sets each comprising four data blocks such that each user data block is a member of one row set and is a member of one vertical set. In another embodiment sets comprise two blocks each.
Claims16
A method comprising:
- defining a grid structure of columns and rows, where said columns each correspond to a storage domain and said rows correspond to a plurality of blocks from the domains;
- designating a contiguous first plurality of the data blocks in said grid as user data blocks arranged in a first plurality of adjacent rows of the grid;
- designating a contiguous second plurality of the data blocks in said grid as parity blocks arranged in a second plurality of adjacent rows of the grid;
- and
- converting the grid from a first RAID format to a second RAID format by redesignating selected parity blocks as free entries.
A data storage architecture comprising:
- a data storage grid comprising columns associated with storage domains and rows associated with equal size data storage blocks of the storage domains;
- and
- a data/parity map designating a contiguous grouping of the data storage blocks as user data blocks in the grid and designating a different contiguous grouping of the data storage blocks as parity blocks in said grid, wherein the user data blocks are further arranged to support a plurality of different RAID levels without movement of said blocks by respectively allocating or returning as free entries selected ones of the parity blocks.
A data storage architecture comprising:
- a grid comprising columns and rows corresponding to storage domains and to equal size data storage blocks, respectively;
- and
- means for converting the grid from a RAID 6 format to a lower RAID format without moving data in the grid by redesignating parity blocks in the grid as free entries.
A data storage system comprising an array of data storage devices and a data storage grid in memory which arranges the storage devices into columns and data storage blocks of said storage devices into rows, wherein the storage grid designates a first contiguous grouping of the data storage blocks as user data blocks and a second contiguous grouping of the data storage blocks as parity blocks with each storage device storing at least one said user data block and at least one said parity block, and wherein the data storage blocks are arranged to support a plurality of different RAID formats without movement of said user data by selectively allocating or returning selected parity blocks as free entries.
Dependencies are inferred from the claim text.