We just downloaded the LiveCycle Virtual Appliance and got it running - looks like a really great piece (better multiple pieces) of great software...
We are actually looking for a way to convert PDF to PDF/A. Is this possible with LiveCycle PDF Generator running on Linux?
Have a look at the DocConverter operations (under common in Workbench). They should work under supported versions of Linux.
If you're still looking for a solution to convert PDF to PDF/A, you might be interested in a utility I found some time ago. It's called Print Transform and it's available on Linux and other systems. You can test the converter for free on their Web site: www.printtransform.com.