Raid array data storage system with storage device consistency bits and raidset consistency bits

摘要

Metadata described herein on a RAID array includes both device metadata and RAIDset metadata. The device metadata has a device FE bit on each storage device corresponding to each RAID protected block on the storage device. The device FE bit indicates if a corresponding RAID protected block is consistent and thereby useable to regenerate data in another RAID protected block in the corresponding RAID protected block's sliver. The user data also has a forced error bit to indicate if a physical block in the user block has inconsistent data, the RAIDset FE bit. The RAID array of storage devices has user data blocks on each storage device RAID protected by being distributed as slivers of blocks across the RAID array of storage devices. Each sliver has a plurality of user data blocks and one parity block. The RAIDset metadata has the RAIDset FE bit corresponding to each RAID protected user data block in the RAID array. The RAIDset FE bit indicates whether or not a corresponding RAID protected user data block contains true data. In addition, FE Dir bits corresponding to each block of FE bits for the device or the RAlDset are added to the metadata. Further the device FE bits, the RAIDset FE bits, the device FE Dir bits and the RAIDset FE Dir bits are in RAID protected blocks in a RAIDset sliver having RAIDset FE bit blocks. RAIDset FE Dir blocks, and a parity block.