Solid-state disk cache-assisted redundant array of independent disks

摘要

A system including a write module to receive first data for writing over second data stored on a first member of a stripe of a RAID. A read module reads the second data and first parity from a SSD or the RAID. Before receiving third data for writing over fourth data stored on a second member of the stripe, the read module reads the fourth data from the second member and stores the fourth data in the SSD. A parity module generates second parity based on the first data, the second data, and the first parity. The write module writes the second parity on the SSD. On receiving the third data, the parity module generates the third parity based on the third data, the fourth data, and the second parity.

主权项

1. A system comprising:
a write module configured to receive first data for writing over second data stored on a first member of a stripe of a redundant array of independent disks (RAID); a read module configured to
read the second data and first parity corresponding to the second data (i) from a solid-state disk (SSD) if the second data and the first parity are stored on the SSD, or (ii) from the RAID if the second data and the first parity are not stored on the SSD, wherein the SSD is separate from the RAID; andin response to (i) the write module receiving the first data and (ii) prior to the write module receiving third data for writing over fourth data stored on a second member of the stripe, (i) read the fourth data from the second member of the stripe, and (ii) store the fourth data in the SSD; and a parity module configured to generate second parity based on (i) the first data, (ii) the second data read from the SSD or the RAID, and (iii) the first parity read from the SSD or the RAID; wherein the write module is configured to write the second parity in the SSD; and wherein the parity module is configured to generate, in response to the write module receiving the third data subsequent to receiving the first data, third parity based on (i) the third data, (ii) the fourth data stored on the SSD, and (iii) the second parity stored on the SSD.