ZFS on top of GELI / Intel Atom 330 system

[Dan Naumov]

Is there anyone here using ZFS on top of a GELI-encrypted provider on
hardware which could be considered "slow" by today's standards? What
are the performance implications of doing this? The reason I am asking
is that I am in the process of building a small home NAS/webserver,
starting with a single disk (intending to expand as the need arises)
on the following hardware:
http://www.tranquilpc-shop.co.uk/acatalog/BAREBONE_SERVERS.html This
is essentially: Intel Arom 330 1.6 Ghz dualcore on an Intel
D945GCLF2-based board with 2GB Ram, the first disk I am going to use
is a 1.5TB Western Digital Caviar Green.

I had someone run a few openssl crypto benchmarks (to unscientifically
assess the maximum possible GELI performance) on a machine running
FreeBSD on nearly the same hardware and it seems the CPU would become
the bottleneck at roughly 200 MB/s throughput when using 128 bit
Blowfish, 70 MB/s when using AES128 and 55 MB/s when using AES256.
This, on it's own is definately enough for my neeeds (especially in
the case of using Blowfish), but what are the performance implications
of using ZFS on top of a GELI-encrypted provider?

Also, free free to criticize my planned filesystem layout for the
first disk of this system, the idea behind /mnt/sysbackup is to take a
snapshot of the FreeBSD installation and it's settings before doing
potentially hazardous things like upgrading to a new -RELEASE:

ad1s1 (freebsd system slice)
	ad1s1a =>  128bit Blowfish ad1s1a.eli 4GB swap
	ad1s1b 128GB ufs2+s /
	ad1s1c 128GB ufs2+s noauto /mnt/sysbackup

ad1s2 =>  128bit Blowfish ad1s2.eli
	zpool
		/home
		/mnt/data1


Thanks for your input.

- Dan Naumov