[gpadmin@yz_dev ~]$ gpssh-exkeys -h 127.0.0.1
[STEP 1 of 5] create local ID and authorize on local host
[STEP 2 of 5] keyscan all hosts and update known_hosts file
[STEP 3 of 5] authorize current user on remote hosts
 ... send to 127.0.0.1
[STEP 4 of 5] determine common authentication file content
[STEP 5 of 5] copy authentication files to all remote hosts
 ... finished key exchange with 127.0.0.1
[INFO] completed successfully