Methods and structure for multi-drive mirroring in a resource constrained raid controller

摘要

Methods and associated structure for mapping of data stripes and stripes in a RAID level 1E storage subsystem such that associated stripes of multiple physical stripes are physically contiguous. This mapping eliminates the need for duplicative reading (or writing) of stripes unrelated to the underlying I/O request performed to reduce the total number of I/O requests. This mapping also serves to limit the number of I/O requests required to read multiple stripes to the number of disk drives in the array and the number required to write multiple stripes and their corresponding mirrors to twice the number of disk drives in the array. The effects of this mapping therefore simplify RAID level 1E management in RAID controller with constrained memory and processing resources.