ZFS Caching

L2ARC (Level Two Adaptive Replacement Cache) is a powerful feature in ZFS that extends the capabilities of the ARC (in-memory cache). When you designate a dedicated disk as an L2ARC device, it acts as a secondary cache layer for frequently accessed data.

This helps accelerate read performance by storing commonly used data blocks on faster storage than your primary pool devices. While ARC is lightning fast due to its RAM location, L2ARC offers larger capacity and can handle data that doesn’t fit within ARC’s limited size.

Step 1: Click on “Add Cache"

Step 2: Select available drive

Step 3: Check if cache is listed in “Pool Members”