doc/rbd: clarify when image_id is expected for import-only migration

"optional if image in trash" can be easily interpreted as "required if
image not in trash".

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
(cherry picked from commit 175ca1e0f0928eed70a735c980c7619214a12cb5)

diff --git a/doc/rbd/rbd-live-migration.rst b/doc/rbd/rbd-live-migration.rst
index 68165c18ae64796f79261b24ad1d004b0b56f8ec..47a19304f8b197047c595d51fb8345562c341870 100644 (file)
--- a/doc/rbd/rbd-live-migration.rst
+++ b/doc/rbd/rbd-live-migration.rst
@@ -165,7 +165,7 @@ as follows::
             ["pool_id": <pool-id>,] (optional alternative to "pool_name")
             ["pool_namespace": "<pool-namespace",] (optional)
             "image_name": "<image-name>",
-            ["image_id": "<image-id>",] (optional if image in trash)
+            ["image_id": "<image-id>",] (specify if image in trash)
             "snap_name": "<snap-name>",
             ["snap_id": "<snap-id>",] (optional alternative to "snap_name")
         }