After four years of SMR storage, here's what we love—and what comes next

This post details Dropbox's continued leadership and learnings in adopting Shingled Magnetic Recording (SMR) technology for its storage drives, now comprising 90% of its HDD fleet. It highlights improvements in storage density through advanced recording techniques (TDMR), increased platter count, and optimized enclosure design. The post also quantifies the power efficiency gains (5-6x decrease in TB/watt) and cost benefits (10-20% more data per drive at similar cost) achieved through SMR adoption. Furthermore, it discusses software ecosystem maturation, including better support for zoned devices via libraries like libzbd and advancements in testing tools like SMRtest. Finally, it emphasizes deeper collaboration with HDD vendors, integrating them into large-scale testing for improved bug reproduction and velocity.