doc/man/ceph: more details on config-key command

Signed-off-by: Kefu Chai <kchai@redhat.com>

diff --git a/doc/man/8/ceph.rst b/doc/man/8/ceph.rst
index 40e71304d5e8ac864c53a842487757d8c3b2b737..801a4a78f6576f5262ff681a7f7e063d104e2c61 100644 (file)
--- a/doc/man/8/ceph.rst
+++ b/doc/man/8/ceph.rst
@@ -177,7 +177,10 @@ Usage::
 config-key
 ----------
 
-Manage configuration key. It uses some additional subcommands.
+Manage configuration key. Config-key is a general purpose key/value service
+offered by the monitors. This service is mainly used by Ceph tools and daemons
+for persisting various settings. Among which, ceph-mgr modules uses it for
+storing their options. It uses some additional subcommands.
 
 Subcommand ``rm`` deletes configuration key.