Patent attributes
A system and method for optimizing accesses to storage devices based on RAID I/O request characteristics is disclosed. A current I/O request processed by a storage controller is analyzed for relative locality to a previous I/O request, and adjusted over time such that storage device accesses will be efficiently conducted with respect to sequential or random workloads. A storage device access profile is maintained for each storage device based on sequential or random locality characteristics of previous RAID I/O requests. The chunk locations of the two most recent accesses are sampled according to predetermined criteria in order to create a storage device access profile, which governs queue depth and I/O size parameters used to communicate with storage devices. By managing I/O requests to storage devices using this invention, performance of such a storage controller will be optimized for changing random and sequential workloads.