doc: describe differences with "mds set" vs "fs set"

Thanks to John Spray <jspray@redhat.com> on ceph-users for this
information.

Signed-off-by: Ken Dreyer <kdreyer@redhat.com>

diff --git a/doc/cephfs/administration.rst b/doc/cephfs/administration.rst
index ccf6263d641c8c647fdd8334616f7de877cc17c7..23bd5fc6a991ed222b42b1b7117166eba01b7be8 100644 (file)
--- a/doc/cephfs/administration.rst
+++ b/doc/cephfs/administration.rst
@@ -158,6 +158,11 @@ filesystem.
 Legacy
 ------
 
+The ``ceph mds set`` command is the deprecated version of ``ceph fs set``,
+from before there was more than one filesystem per cluster. It operates
+on whichever filesystem is marked as the default (see ``ceph fs
+set-default``.)
+
 ::
 
     mds stat