The following VirtualBox appliance is an OmniOS install configured to demonstrate the benefits of ZFS for PostgreSQL
Make sure you download and follow the instructions for setting up VirtualBox prior to importing the appliance.
NOTE This version of the VM has fixed the problem encountered during the tutorial at PGCon. If you want the thrill of fixing the problem yourself, follow these instructions. You will probably learn a few things about zones and zfs along the way.
The VirtualBox Appliance: OmniOS-pgcon-2.ova ~2GB
Tutorial slides from PGCon 2012 postgresOnZFS.pdf