I have done the instructions listed here: How to move Bitcoin data from Application Support on an external drive [Mac]
It works fine for a flash drive connected the mac, but I wanted to have the data read from my network storage device (ReadyNAS). Bitcoin-qt comes up with the following error when I link it to the NAS:
EXCEPTION: N5boost12interprocess22interprocess_exceptionE
Operation not supported
bitcoin in Runaway exception
Any ideas on what this could be?