> Also, I wonder how well ZFS works with just 128MB of RAM.
> Does anybody here have experience trying to get a couple TB worth of ZFS storage on a low-end machine?
128MB of RAM is an absurdly low amount for a NAS server. You might as well run a webserver on an Apple IIgs while you're at it. Performance will be terrible regardless of filesystem type, since you can't take advantage of prefetching and caching.
My Netgear ReadyNAS (Linux/SPARC) has 1GB of RAM and it's over a year old. Surely the hardware available now has more than 128MB of RAM.