Encryption and ZIL/L2ARC setup

[David E]

Hi All-
Two questions, if you don't know the answer to both, feel free to tackle just one :)

1) I read in the docs somewhere that the L2ARC cache is not encrypted, why? I'd like to put mine on SSDs, so presumably the full SSDs could be encrypted?

2) I have 2 128GB SSDs that I'd like to use for a combination of L2ARC/ZIL devices. I'd like to take 32GB of each SSD and mirror it, and make that the ZIL. Then take the remaining 92GB on each drive, stripe it (total 192GB) and make that an L2ARC. Is this something I can configure using the web interface? Guessing not, and if not, can I do it at the console without goofing up my ability to use the web interface for other tasks?

Thanks!

 

[cyberjock]

1. The whole point of the L2arc is to decrease latency. That's not necessarily going to be as effective if its encrypted. The encryption FreeNAS uses is geli. It's not ZFS's encryption as that's not open source. You can easily do it from the CLI if you really want it. But you shouldn't be surprised if it doesn't work out well for you.

2. If you search around the forums, the zil and l2arc shouldn't go on the same device. The 2 compete and neither one ends up doing their job well. I even mentioned this in my noobie presentation if I remember correctly. Just like I said above, it can be done from the CLI. But don't be surprised if you have problems with FreeNAS if you do it that way.

FreeNAS gives you access to the most commonly used configurations for simplicity. The consequence is that you don't have full control like you would with FreeBSD. If you are really wanting to go and do these things you might be better off with a full installation of FreeBSD instead.

 

[David E]

Thanks that makes sense, and I guess if the ZIL only has at most a couple GB of data the exposure is pretty low. Is there a need to run SSDs fronting a ZIL in a mirror? Or is a single device sufficient?