I have a 512GB memory system that has a 480GB (or so) L2ARC, and a
raidz2 storage pool. No dedup or compression is enabled. Although, I
will enable compression in the future.
By default vfs.zfs.arc_max is about 300GB and the L2ARC is hardly touched.
I've seen a couple hints recently on the
Try to read through the email thread I have started and specifically posts
(replies) by alc:
http://lists.freebsd.org/pipermail/freebsd-performance/2012-August/thread.html#4640
I have followed his suggestions, and with the arc_max setting I used we
still have on average free RAM ~137GB.
HTH.
