ceph/ceph — pull request #945 by dachary (2013-12-15 14:38:30+00:00)
Title: ceph-disk: zap needs at least one device

If given no argument, ceph-disk zap should display the usage instead of
silently doing nothing. Silence can be confused with "I zapped all the
disks".

http://tracker.ceph.com/issues/6981 fixes #6981

Signed-off-by: Loic Dachary