Hi,
ownCloud is not designed to sync files between servers. In addition the current stage of integration doesnt support multiple ownCloud servers in one UCS-domain (at least in a consistent way and with the ability to define which user is defined on which system).
What can be done with ownCloud is to have a central ownCloud system which consolidates multiple storage sources including those served on remote locations.
You will need to configure External Storage Support or Windows Network Drive (WND). (WND needs a subscription of “ownCloud by it25” or “ownCloud Enterprise”).
The other approach would be the bi-directional sync of files/folders or blockdevices between the UCS-systems. DRBD is available on UCS but might require a subscription to use DRBD-Proxy. I dont know if someone already used Ceph oder GlusterFS on UCS.
I have heared that running Syncthing on UCS is possible. It might be possible to configure to sync folders between 2 or more servers.
Best Regards,
Dirk Ahrnke