Proposes a new way of managing flash memory space for flash memory-specific file systems based on a log-structured file system. Flash memory has attractive features such as non-volatility and fast I/O speed, but it also suffers from an inability to update in place, and limited usage cycles. These drawbacks require many changes to conventional storage (file) management techniques. Our focus is on lowering the cleaning cost and evenly utilizing flash memory cells while maintaining a balance between these two often-conflicting goals. The cleaning efficiency is enhanced by dynamically separating cold data and non-cold data. The second goal, cycle leveling, is achieved to the degree where the maximum difference between erase cycles is below the error range of the hardware. Simulation results show that the proposed method has a significant benefit over naive methods: a maximum of 35% reduction in the cleaning cost with evenly-spread writes across segments.
['Han-Joon Kim', 'Sang-goo Lee']
A new flash memory management for flash storage system