En attendant, sur des 20M+ files :

# En direct
cd /mnt/source && tar -c . | tar -C /mnt/dest -x
# Vers remote server
cd /mnt/source && tar -c . | ssh remote-machine "cd /mnt/dest && tar -x"

Voir http://www.highmotionsoftware.com/products/imbatch

Via river.

The DebOps project provides a set of general-purpose Ansible roles that can be used to manage Debian or Ubuntu hosts. In addition, a default set of Ansible playbooks can be used to apply the provided roles in a controlled way, using Ansible inventory groups.