pages to the free block (Merge) 3. Erase victim blocks → free block GC incurs 1. Increase response time of user request 2. Increase # of P/E cycle(lifetime)
blocks containing hot and cold data cause partial & full merge → hot(or cold) data blocks will be switch-merged 2. When to begin On-demand: prevents user request because of merge operation Background: high managing cost(GC scheduling) 3. Victim block selection: Which block to reclaim blocks that minimize merging cost and have low P/E cycle
Multi-Stream SSD: write data to different block each stream Open-Channel SSD: Manage FTL in host side Optane DIMM(non-volatile memory): Use low-latency ssd as a memory Key-Value SSD: Offload storage engines of KV store (e.g, wired tiger) into SSD