fix typo in ceph-volume lvm prepare help

Signed-off-by: Jeffrey Zhang <zhang.lei.fly@gmail.com>

diff --git a/src/ceph-volume/ceph_volume/devices/lvm/prepare.py b/src/ceph-volume/ceph_volume/devices/lvm/prepare.py
index 06f7ef8b59ba2484d714034233d6e5b1f7773c46..a46abcf53d3e3f4f7b19b29498cd79610f491f80 100644 (file)
--- a/src/ceph-volume/ceph_volume/devices/lvm/prepare.py
+++ b/src/ceph-volume/ceph_volume/devices/lvm/prepare.py
@@ -325,7 +325,7 @@ class Prepare(object):
 
         Optionally, can consume db and wal devices or logical volumes:
 
-            ceph-volume lvm prepare --data {vg/lv} --block.wal {device} --block-db {vg/lv}
+            ceph-volume lvm prepare --data {vg/lv} --block.wal {device} --block.db {vg/lv}
         """)
         parser = prepare_parser(
             prog='ceph-volume lvm prepare',