HSMR-RAID: Enabling a Low Overhead RAID-5 System over a Host-managed Shingled Magnetic Recording Disk Array

Some previous studies have been proposed to alleviate the impact of the frequently-updated parity data on an SMR-based RAID 5 storage system through the integration of extra hardware devices. They always utilize solid-state drives as a buffer to absorb the impact of random write operations on the SMR-based storage system performance. Unlike previous studies, this work proposes an SMR-friendly RAID 5 storage system, namely HSMR-RAID, that is developed on a pure SMR environment without any additional storage drives. The HSMR-RAID is based on a host-managed SMR architecture. The principle of HSMR-RAID is to exploit the benefits brought by data information from the host system side to put data blocks that would be invalidated at the same time in the same stripe. By this principle, we can reduce the amount of data movement and recalculate parity data so as to minimize garbage collection overhead. According to our experiments, the proposed scheme can speed up garbage collection performance by up to 29%.