diff --git a/doc/admin-guide/files/storage.config.en.rst b/doc/admin-guide/files/storage.config.en.rst
index d66a2711a50..aa417365dd7 100644
--- a/doc/admin-guide/files/storage.config.en.rst
+++ b/doc/admin-guide/files/storage.config.en.rst
@@ -184,3 +184,10 @@ following rules are stored in :manpage:`devfs.conf(5)`::
 
    # Assign /dev/ada1 and /dev/ada2 to the tserver user
    own    ada[12]  tserver:tserver
+
+Advanced
+--------
+
+Because relative paths in :file:`storage.config` are relative to the base prefix, when using customized runroot
+it may be necessary to adjust such paths in :file:`storage.config` or adjust ``runroot_path.yml`` itself.
+Despite the name, the cachedir value is not used for this file.
diff --git a/doc/appendices/command-line/traffic_layout.en.rst b/doc/appendices/command-line/traffic_layout.en.rst
index a330c8d8ab3..8e54d935dd1 100644
--- a/doc/appendices/command-line/traffic_layout.en.rst
+++ b/doc/appendices/command-line/traffic_layout.en.rst
@@ -102,6 +102,11 @@ Below is an example of customized yaml file (custom.yml) to construct. ::
 
 If ``traffic_layout init --layout="custom.yml"`` is executed, a runroot following the format above will be created.
 
+.. Note::
+
+   :file:`storage.config` does not use the cachedir value, but makes its relatives paths relative to the base prefix.
+   So please update the directory for cache in ``storage.config`` according to the customized runroot.
+
 remove
 ------
 Find the sandbox to remove in following order:
@@ -138,6 +143,10 @@ Options
 
     Print usage information and exit.
 
+.. option:: --path
+
+    Specify the path of runroot for commands (init, remove, verify).
+
 init
 ----
 .. option:: --force