Replica much smaller than original OK?

Hi. I have an existing IdM server running ipa-server-4.2.0-15.el7_2.17.x86_64. It has been around for a few years (created by my predessessor) and it manages about 150 users and 650 hosts. It also has a replica at the same software level.
I have now built a 3rd server, installed ipa-server-4.5.0-22.el7_4.x86_64, and replicated from the first server. All the messages indicate that it has replicated successfully, and function seems to all be there, although I have not yet tried running with only the new server yet. However, the disk use is very much smaller on the new server – du -ms /var/lib/dirsrv/ says 9163 on old server, and 114 on new !? Likewise, the ipa-backup file is much smaller – 487 MB on old and 14 MB on new.
My guess is that the replication has left behind old cruft and historical stuff – can anyone confirm if that is right please, and how to check for sure that the new server has everything it needs from the old?
Thanx.