The directadmin to directadmin migration is easy.
1) Set the value skip_domains_in_backups=1 in /usr/local/directadmin/conf/directadmin.conf . This will skip coping home folder during backup creation.
2) Do to admin panel Admin Tools -> Admin Backup/Transfer , And select all users and run a backup now .This will take all accounts backups under the folder /home/admin/admin_backups..
3) Now login to the admin panel of the new server and go to Admin Tools -> Admin Backup/Transfer , then select the “restore backups “. Chose all the backups files and click the submit.
4) Monitor the new server and wait for finishing the restore. You can check the top comand and or use pstree. See if the comamnd dataskq completed or not. Also check the home folders .
5) After finishing it simply rsync the home folders.