Without NVRAM and proper software support, MD/RAID-456 has not been very competitive against hardware RAID in enterprise use cases. Particularly, MD/RAID-456 suffers from potential data loss during unexpected shut down (the write hole); and long write latency from read-modify-write updates (slow fsync). With recent development in NVRAM (NVMe SSD, NVDIMM), it is now possible to bring enterprise level reliability and performance to MD/RAID-456. In this presentation, Song Liu will present joint work with Shaohua Li in MD/RAID-456 write journal and write back cache.
