https://community.cloudera.com/t5/Support-Questions/The-DataNode-is-not-connected-to-one-or-more-of-its-NameNode/m-p/45197#M46133 <P>I think i'm having many problems, there are 12 severe health issues and my agent is also not running. i'm getting the following error message.</P><P>&nbsp;</P><PRE> This host has been out of contact with the Cloudera Manager Server for too long. This host is not in contact with the Host Monitor.</PRE><P>They have suggested 3 actions which are;</P><P>&nbsp;</P><PRE> Change Host Process Health Test for all hosts Change Host Process Health Test for this host Upgrade the Cloudera Manager Agent software</PRE><P>Please suggest which action i has to take.</P><P>&nbsp;</P><P>Also since i'm completely new to Apache hadoop and Cloudera, kindly suggest where i has to start CHD or Clouder quick start vm. Also what is the difference between CDH &amp; quickstart vm.</P><P>&nbsp;</P><P>Thanks,</P><P>Karthi</P> Fri, 16 Sep 2016 17:09:37 GMT karthi8 2016-09-16T17:09:37Z