ZFS - moving from a zraid1 to zraid2 pool with 1.5tb disks

[Josef Karthauser]

On 7 Jan 2011, at 17:30, Artem Belevich <fbsdlist at src.cx> wrote:
> One way to get specific ratio for *your* pool would be to collect
> record size statistics from your pool using "zdb -L -b <pool>" and
> then calculate L2ARC:ARC ratio based on average record size. I'm not
> sure, though whether L2ARC stores records in compressed or
> uncompressed form.

Can someone point me to a reference describing the various zfs caches available? What's the arc and zil? Ive been running some zfs for a few years now, and must have missed thus entire subject :/.

Joe