diff --git a/doc/source/advanced_deployment/baremetal_overcloud.rst b/doc/source/advanced_deployment/baremetal_overcloud.rst
index 566ff396..7c16fdee 100644
--- a/doc/source/advanced_deployment/baremetal_overcloud.rst
+++ b/doc/source/advanced_deployment/baremetal_overcloud.rst
@@ -484,6 +484,15 @@ command to get the last error::
 
     openstack baremetal node show <UUID> -f value -c last_error
 
+With the switch to cell_v2 in Ocata (and on), it's now needed to search for cells, or a single cell,
+and map found hosts, which are not currently mapped. The following command needs to run once on one
+controller node::
+
+    sudo nova-manage cell_v2 discover_hosts --verbose
+
+.. note::
+    More information about cells is available here: https://docs.openstack.org/developer/nova/cells.html
+
 Checking available resources
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