To export users you can use the following script:
Make sure the script is executable once you have downloaded it.
chmod 755 clustrix_clone_users
The script will get the grants for all users in a way that's ideal for backup and import purposes. For example:
./clustrix_clone_users -H myhost -u root >> user_dump.sql
This can then be imported into Clustrix like:
mysql -uroot -h <clustrix IP> < user_dump.sql
For more information on clustrix_clone_users, please see the README