Re: Wow
Err, no, apparently you didn't, judging by your explanations.
ZIL turns sync operations into async operations. It is only ever read on an unclean shutdown. It isn't a write cache. Buffering is done in RAM.
L2ARC is populated by what is evicted from ARC and reset on export/reboot. Unless you have a very long running system with a working set that significantly exceeds your RAM, L2ARC will be we get even populated, let alone used.
Various things never get cached in ARC (e.g. IIRC sequential reads), because the win is typically not big enough. If it doesn't get cached in ARC, it will never be in L2ARC. So I'll hazard a guess your testing didn't account for anything but the naive case of cat-ing big files to /dev/null.
Biting the hand that feeds IT
