Recommendations for vSphere 5.1?

In Oracle's document on partition alignment for the ZFS Appliance 7000 Series, they state, "When setting up a share on the Sun ZFS Storage Appliance, make sure you set the ZFS volume block size to a value that is optimal for your (virtual) application environment. In the Sun ZFS Storage Appliance BUI, use the property option 'Database record size’ in the share Properties window.

Any recommendations on how I should determine what that value should be? While it was a good document overall, there were no recommendations on how to determine what is optimal. I was also wondering what the best default Volume block size should be for File Systems (or how to determine what's optimal for this as well).