I agree the links are confusing and I will address that in the next doc update.    The prepare script is not installed until after you install the Cloudera Manager packages. You install and configure the external database as described in MySQL Database , Oracle Database , or External PostgreSQL Database .   After you install the Cloudera Manager packages (Install the Cloudera Manager Server Packages), you run the database setup script as described here: Preparing a Cloudera Manager Server External Database. ... View more

To get to the client environment safety value, do this:   Go to the MapReduce service status page. Select Configuration > View and Edit. Expand Gateway (Default) > Advanced. Click MapReduce Client Environment Safety Valve for hadoop-env.sh.   ... View more