Drive-Assisted RAID Parity Update Mechanism

The patent segments the RAID functionality by separating the RAID storage controller into two parts: a host processor that initiates RAID operations, and storage devices that autonomously perform parity computations and data reconstruction. This segmentation moves complex processing from the controller to the storage devices themselves, reducing the processing burden on the RAID storage controller while maintaining data redundancy through distributed parity calculations across multiple storage devices.

The patent implements a feedback mechanism where storage devices send completion notifications back to the host processor indicating when parity data has been successfully updated. The host processor tracks the completion status of all parity updates for a given stripe and only confirms write completion when all parity updates are finished. This feedback loop ensures parity consistency is maintained while allowing the system to proceed with reduced I/O operations, as the host processor coordinates based on actual completion status rather than waiting for all operations to finish sequentially.

The patent enables storage devices to serve themselves by autonomously performing parity computations and data reconstruction operations without requiring continuous intervention from the RAID storage controller. Each storage device independently calculates its portion of parity data and manages its own update operations, reducing the processing burden on the controller and improving write performance by parallelizing operations across multiple storage devices.

The patent implements preliminary action by having storage devices pre-compute parity data and prepare for updates before actual write operations complete. Storage devices calculate parity data in advance and stage it for immediate writing, reducing the time required during actual write operations. This preliminary computation allows the system to maintain data redundancy while minimizing the time lost to I/O operations, as parity data is ready when needed rather than computed during the write process.