I am trying to add two more hosts to my existing cluster (only has one right now) but I am running into errors during the Ambari step - Confirm Hosts. The error message is shown below. It says it failed because it finished with a non zero exit code. What does this mean and how can I fix it? I have followed the steps to configure passwordless ssh but I may have done something incorrectly. I have replace the host name with a bunch of x's. ========================== Creating target directory... ========================== Command start time 2016-02-23 10:45:50 Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password). SSH command execution finished host=xxxxxxxxxxxxxxxxxxxxx, exitcode=255 Command end time 2016-02-23 10:45:51 ERROR: Bootstrap of host xxxxxxxxxxxxxxxxxxxx fails because previous action finished with non-zero exit code (255) ERROR MESSAGE: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password). STDOUT: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password). ... View more