JBoss ON agent.log file filled up with "Permission denied" messages when trying to access $JON_AGENT_HOME/data folder

Issue

• JBoss ON agent logs constantly messages like:

  ... DEBUG [main] (org.rhq.enterprise.communications.ServiceContainer)- {ServiceContainer.identity-failure}The machine hostname does not seem to be resolvable - generating our own identity. Cause: java.lang.RuntimeException: Exception creating identity: java.lang.RuntimeException: Error creating Instance ID: java.io.IOException: Permission denied
  ...
  ... WARN  [RHQ Agent Registration Thread] (org.rhq.enterprise.agent.AgentMain)- {AgentMain.failover-list-cannot-be-persisted}The server failover list cannot be persisted to [data/failover-list.dat]. Cause: java.io.FileNotFoundException:data/failover-list.dat (Permission denied)
  java.io.FileNotFoundException: data/failover-list.dat (Permission denied)
  ...
  ... ERROR [main] (rhq.core.pc.plugin.PluginManager)- Plugin [CXF] at [file:/rhq-agent/plugins/cxf-plugin-7.3.1.redhat-379.jar] could not be loaded and will therefore not be deployed.
  org.rhq.core.clientapi.agent.PluginContainerException: Failed to unpack embedded JARs within: file:/rhq-agent/plugins/rhq-jmx-plugin-4.12.0.JON330GA.jar
  ...
  Caused by: java.io.IOException: Permission denied
  ...
  ... WARN  [main] (rhq.core.pc.inventory.InventoryManager)- Could not create data dir /rhq-agent/data/rc/35
  ...
  

• JBoss ON agent is not able to download all plugins from the JBoss ON server;