| 摘要 |
A RAID disk array controller implements a write mask to support partial-stripe updates from a host system without expensive RAM to RAM copying and repeated disk accesses to assemble the updated stripe. New data from the host is transferred into a single buffer and a local processor tracks-by setting bits in the write mask-which segments of the target stripe are updated. The disk array is accessed to transfer the target stripe into the same buffer, but the buffer memory write enable is inhibited-responsive to the write mask-during transfer of the segments that were updated by the host. The complete, updated stripe is thus formed in a single buffer for parity calculations and write to the disk array.
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