nfs send error 65

Proceeding with my Christmas presents, I have refactored my ${HOME} lab. One of the goals was to migrate my public gateway to a diskless Soekris Net6501 my beloved wife offered me :) The overall PXE/NFS process is explained a billion times over the Internet, only particular point here is that I used dnsmasq instead of ISC DHCP. Nevertheless I came across an issue that took me way too long to understand; while the boot process seemed perfectly fine, at some point, after Setting up ttys, init hung and the kernel showed the following message: