just for the records:
# echo ${HOSTNAME}
pre01svdeb02
# hostname -f
pre01svdeb02.pilsbacher.at
# cat /etc/hosts
127.0.0.1 localhost
192.168.16.205 pre01svdeb02.pilsbacher.at
# The following lines are desirable for IPv6 capable hosts
::1 localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters