DT-GC: Adaptive Garbage Collection with Dynamic Thresholds for SSDs

Solid state drives (SSDs) are rapidly growing used in both personal computer and enterprise server area in the past several years. Compare with traditional hard disk drive, the advantages of SSDs are great performance, small size and shock resistance. However, SSDs suffer from obvious performance dropping when free physical pages become lacking, after plenty of data writing. Because time-consuming garbage collection has to be ran to gaining enough free pages. Most algorithms determine a certain threshold of free page proportion, which could not adapt to various application environments, to trigger the garbage collection process. To achieve efficient garbage collection in most application environments, we propose DT-GC, an adaptive garbage collection method with dynamic thresholds. In such scheme, garbage collection request with different priority could be triggered intelligently by dynamic thresholds, which are determined by the running state of SSDs.