Various improvements

- Move switch spec from Aether to SD-Fabric. Update the list
- Move ONIE/ONL deployment/troubleshooting section from Aether to SD-Fabric

Change-Id: I3eaeb839f8e1fc595a775c305246c7659bb82cdb
diff --git a/troubleshooting.rst b/troubleshooting.rst
index 5169dc3..981072e 100644
--- a/troubleshooting.rst
+++ b/troubleshooting.rst
@@ -11,6 +11,19 @@
 control plane software and data plane software are containerized and deployed as Kubernetes services in SD-Fabric.
 Please refer to :ref:`architecture_design` for further details.
 
+ONL troubleshooting
+-------------------
+
+Can't reboot into ONL, loops on ONIE installer mode
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Sometimes an ONL installation is incomplete or problematic, and reinstalling it
+doesn't result in a working system.
+
+If this is the case, reboot into ONIE Rescue mode and use ``parted`` to delete
+all the ``ONL-`` prefixed partitions, then reinstall with an ``onie-installer``
+image.
+
 K8s troubleshooting
 -------------------