What is the L2ARC?
The L2ARC is the second level Adaptive Replacement Cache. The L2ARC acts very much like a victim cache for the primary cache. The 7000 moves cached data and metadata that is about to be evicted from primary cache to the readzilla. It is important to note that it moves data that is about to be evicted, not data that was just evicted. This makes a major difference in system performance.