mitigating write/update latency in smr drives

Shrey Gupta, Avani Wildani

Shingled Magnetic Recording (SMR) is a data storage technology that is a recent innovation in the domain of storage recordings/drives. Unlike Conventional Magnetic Recording (CMR) where data is written on tracks that are parallel to each other, an SMR has overlapping tracks that are organized as shingles on a roof. The utility of such an architecture is that it increases the areal density of the disk and ergo the capacity. Hence, the overlapping of the tracks improve the areal density of the disk but also reduces its write and update efficiency i.e during the write process, the contents of the bottom track is overwritten as well. This creates a pitfall for random write operation and hence, the SMR drives usually follow the sequential write model.

Scope

We review the improvements in the write/update technology for the SMR drives and look at how they address this problem. We analyze these techniques for their peak performance and understand their limitations and inconsistencies. We would then try to address these findings with out own technique that tries to incorporate the a culmination of the above techniques in the most effective way.