doc: Usage requires --num_osds.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>

diff --git a/doc/man/8/crushtool.rst b/doc/man/8/crushtool.rst
index 441f6b9e383df2cd7e5a6bbde6b55fd3504c5765..187352a5c040551e01dae897a40dc924a151b818 100644 (file)
--- a/doc/man/8/crushtool.rst
+++ b/doc/man/8/crushtool.rst
@@ -36,7 +36,7 @@ The tool has four modes of operation.
    will take the compiled map and decompile it into a plaintext source
    file, suitable for editing.
 
-.. option:: --build numosds layer1 ...
+.. option:: --build --num_osds {num-osds} layer1 ...
 
    will create a relatively generic map with the given layer
    structure. See below for examples.