Dear, I am trying to install replica by "ipa-replica-install replica-info-namenode2.hadoop.gxdwdc.gpg" but it failed, ipa-replica-install replica-info-namenode2.hadoop.gxdwdc.gpg...The host namenode2.hadoop.gxdwdc already exists on the master server.You should remove it before procedding: % ipa host-del namenode2.hadoop.gxdwdc Then I ran "ipa -host-del namenode2.hadoop.gxdwdc" but it still failed,[root@namenode2 ~] ipa host-del namenode2.hadoop.gxdwdcipa: ERROR: did not receive Kerberos credentials I thought i need to run "kinit" first, than I ran "kinit admin", it still failed,[root@namenode2 ~] kinit adminkinit: Configuration file does not sepcify default realm when parsing name admin can anyone inform me how can i overcome this issue? Thanks ahead.