my response was specific to the question that had asked in comment # 4. I completely agree that a cluster aware app would ensure data consistency across shared disks. However IMO if the writes are well controlled and none of the tasks that lead to metadata changes are performed things should be fine. In anyway this is my personal opinion and I haven't tried this but I am sure linux geeks would have a better answer.
-Arun
http://highoncloud.blogspot.in/
About VMware Virtualization on NetApp