XFS file system
Logical Volume Manager – version 2
Ext3 with journal file version 2
SAMBA/CIFS, AFP, FTP and NFS v2 and v3. We don't support NFS v4 yet.
Download the demo-cd to test for 30 days this will help with other questions you may have and the manual is included.
I guess supporting NFS V4 with all options will take a while...didn't see that much production ready implementations yet. Especially the pNFS feature asks for a different architecture...the current way Open-E (and others) work will make implementation of pNFS very hard....it needs a separate metadata server.