How the defragmentation working?

Hello,as described in this article Defragmentation, aerospike puts a block less than defrag-lwm-pct to the defragmentation queue.So,What’s the next step?What’s goal the defragmentation progress want to reach?How the defragmentation progress to work when a block queued up on the defragmentation queue?

The in-use portions of a block being defragged are written to a block that defrag is filling. Once defrag has filled a block, blocks used to fill it are moved to the free queue and defrag gets a new block from the free queue to fill.

Take a look at Aerospike’s Automatic Storage Reclamation Processes in the deployment docs.