Usually on serves you can't get enough entropy from /dev/random so /usr/sbin/rndc-confgen -a -u named Blocks forever. I would recommend using: /usr/sbin/rndc-confgen -r /dev/urandom -a -u named
since 9.2.5-r10, 9.3.1-r8 and 9.3.2_beta2-r2 ebuild will try to use /dev/ urandom, if it exists and it's a character device. thanks for suggestion, Michal.