I was able to recreate your error and was able to determine the problem.   Your name resolution is not configured correctly.  I am assume you first installation is for demo purposes and is on a local network.  If so, here is what you need to do:   1. Change the machine's name to Fully Qualified Domain Name.  The following is what I did:   # hostname cdn.example.local The .local domain is not routable.  Don't use example.com, because, surprisingly, the Cloudera manager found a machine with the same name on the Internet.   2. Edit the /etc/hostname file with the following:   cdh.example.local 3. Edit the /etc/hosts file by commenting out the entries that begin with 127.0.1.1. and adding an entry the corresponds to your IP address and hostname.  My IP address was 192.168.1.7 and my hostname is cdn.example.local.     #127.0.0.1 localhost #127.0.1.1 cdh.example.local cdh 192.168.1.7 cdh.example.local cdh   After modifying your /etc/hosts file, the changes should take place immediately.  If you still run into installation errors, restart the machine.   4. Edit the /etc/sysctl.conf file to disable IPv6.  Add the following at the end of the file:   net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 net.ipv6.conf.lo.disable_ipv6 = 1   ... View more