Handling partial stripe writes in log-structured storage

摘要

A system and method for writing data a series of partial stripe writes to a redundant array of independent disks (RAID) with parity system. In one embodiment, the RAID with parity system is implemented as a log-structured storage system. In the RAID with parity system, each of the partial stripe writes can be issued before the active stripe is fully written. To buffer each partial stripe write, some data from each partial stripe write can be written to a scratch stripe before being written to the active stripe so that only writes of a predetermined size are issued to the active stripe. Other embodiments are also described herein.

主权项

1. A method for writing data to a redundant array of independent disks (RAID) with a parity system comprising:
allocating a scratch stripe in the RAID system, the scratch stripe composed of scratch units; pairing the scratch stripe with an active stripe in the RAID system, the active stripe composed of data units including an active data unit and at least one parity unit; receiving a first partial stripe write and a second partial stripe write; sending a first scratch write to a first scratch unit of the scratch stripe, wherein the first scratch write includes first data of the first partial stripe write; sending a second scratch write to a second scratch unit of the scratch stripe, wherein the second scratch write includes the first data of the first partial stripe write and second data of the second partial stripe write.