Reporting logical sector alignment for ATA mass storage devices

摘要

Systems and methods for using RAID with ATA mass storage devices can benefit from operating system optimizations for avoiding unaligned write accesses. When the ATA mass storage devices in the RAID array have different physical sector sizes, the largest physical sector size is reported as the physical sector size for the single disk represented by the RAID array. The operating system can optimize accesses that are aligned with all of the physical sector sizes within the RAID array. Additionally, any storage devices that have a first logical sector that does not have an offset of zero, are configured to ignore all logical sectors in the first physical sector. Accesses to the first logical sector are mapped to the second physical sector. A logical sector alignment of zero is then reported to the operating system for the RAID array, enabling the operating system to avoid unaligned writes.