L2ARC in a md(4) device created on FreeNAS-ROOT

[viniciusferrao]

Hello,

I finally managed to get a FreeNAS@home and the system is installed on a 128GB Sandisk SSD. The machine have two pools:

6x 2TB Disks in a RAID-Z2 config
2x 1TB Disks in a Mirrored config

The SSD is underused in this machine since it boots FreeNAS. I was wondering if I can use it as L2ARC device too. To achieve this I've came a across a solution involving mdconfig(8) and an image file on the SSD drive.

It's theoretically possible, but... it should be done?

 

[m0nkey_]

The SSD is underused in this machine since it boots FreeNAS. I was wondering if I can use it as L2ARC device too. To achieve this I've came a across a solution involving mdconfig(8) and an image file on the SSD drive.

Certainly not the recommended way to do it.

First, is there a reason as to why you need a L2ARC device? I'm asking because you haven't posted your hardware specifications. Is your ARC hit ratio way below 80%?