modified: docs/getting-started-guides/ubuntu/index.md

* adding Operational Considerations section
modified:   docs/getting-started-guides/ubuntu/logging.md
	* Moving logging section from operational-considerations.md to logging.md
renamed:    docs/getting-started-guides/ubuntu/operations.md -> docs/getting-started-guides/ubuntu/operational-considerations.md
	* mapping to the proposed name
	* ditched CDK naming in favor of k8s or cluster
	* add whitelines for titles

docs/getting-started-guides/ubuntu/logging.md

@@ -18,3 +18,43 @@ The `juju debug-log` will show all of the consolidated logs of all the Juju agen
 See the [Juju documentation](https://jujucharms.com/docs/stable/troubleshooting-logs) for more information.
 
 
+## Managing log verbosity
+
+Log verbosity in Juju is set at the model level. You can adjust it at any time:  
+
+```
+juju add-model k8s-development --config logging-config='<root>=DEBUG;unit=DEBUG'
+```
+
+and later
+
+```
+juju config-model k8s-production --config logging-config='<root>=ERROR;unit=ERROR'
+```
+
+In addition, the jujud daemon is started in debug mode by default on all controllers. To remove that behavior edit ```/var/lib/juju/init/jujud-machine-0/exec-start.sh``` on the controller node and comment the ```--debug``` section. 
+
+It then contains: 
+
+```
+#!/usr/bin/env bash
+
+# Set up logging.
+touch '/var/log/juju/machine-0.log'
+chown syslog:syslog '/var/log/juju/machine-0.log'
+chmod 0600 '/var/log/juju/machine-0.log'
+exec >> '/var/log/juju/machine-0.log'
+exec 2>&1
+
+# Run the script.
+'/var/lib/juju/tools/machine-0/jujud' machine --data-dir '/var/lib/juju' --machine-id 0 # --debug
+```
+
+Then restart the service with: 
+
+```
+sudo systemctl restart jujud-machine-0.service
+```
+
+See the [official documentation](https://jujucharms.com/docs/stable/models-config) for more information about logging and other model settings in Juju. 
+