diff --git a/doc/install-guide/source/environment-etcd-obs.rst b/doc/install-guide/source/environment-etcd-obs.rst
index 4d9186ad07..3709428cad 100644
--- a/doc/install-guide/source/environment-etcd-obs.rst
+++ b/doc/install-guide/source/environment-etcd-obs.rst
@@ -6,6 +6,8 @@ Right now, there is no distro package available for etcd3. This guide uses
 the tarball installation as a workaround until proper distro packages are
 available.
 
+The etcd service runs on the controller node.
+
 Install and configure components
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/doc/install-guide/source/environment-etcd-rdo.rst b/doc/install-guide/source/environment-etcd-rdo.rst
index 74f78624b9..660bbddbbe 100644
--- a/doc/install-guide/source/environment-etcd-rdo.rst
+++ b/doc/install-guide/source/environment-etcd-rdo.rst
@@ -6,6 +6,8 @@ OpenStack services may use Etcd, a distributed reliable key-value store
 for distributed key locking, storing configuration, keeping track of service
 live-ness and other scenarios.
 
+The etcd service runs on the controller node.
+
 Install and configure components
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/doc/install-guide/source/environment-etcd-ubuntu.rst b/doc/install-guide/source/environment-etcd-ubuntu.rst
index 10fb4309ac..48c853d002 100644
--- a/doc/install-guide/source/environment-etcd-ubuntu.rst
+++ b/doc/install-guide/source/environment-etcd-ubuntu.rst
@@ -6,6 +6,8 @@ OpenStack services may use Etcd, a distributed reliable key-value store
 for distributed key locking, storing configuration, keeping track of service
 live-ness and other scenarios.
 
+The etcd service runs on the controller node.
+
 Install and configure components
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~