As of version 2.4.1, Hockeypuck must no longer be shut down first in order to dump keyfiles. Upgrading to 2.4.1 is strongly recommended for anyone who creates dumps, as it fixes several issues with the dump process, including data loss.
hockeypuck-dump -config /etc/hockeypuck/hockeypuck.conf -path /path/to/keyfiles
This will create files sequenced as hkp-dump-NNNN.pgp.