2-way synchronisation across WAN – DFS, Synology

dfs-rsynchronizationsynology

our office is soon to get a little sister-office in another location. I'm struggling to understand how for example DFS could help get a proper 2-way-synchronisation done between the two locations – and it appears to be difficult to find professional support somewhere for this particular problem…
We currently have:
– a Windows 2003 SBS Server (hosting a DFS at the moment to enable us to have a shared drive across the server and the Synology NAS)
– A Synology Diskstation 1812+
– A Windows 2003 R2 server (set up as a Terminalserver)
– The offices are connected with a medium-good internet connection and a transparent VPN

As it is often the case, the budget is limited. My thought was to transfer the Terminalserver to the new office, which could (could it?) act as the DFS link, and buy another Diskstation for the actual storage.
The Synology sync products don't yet appear (as suggested by many frustrated forum posts) to be good or stable enough to do a 2-way shared folder or cloud station synchronisation.

If I were to move the Terminalserver to the new office, and include it as a DFS destination for the files, how would DFS know that it is a WAN link? Say I have \domain.local\share that is on Server A (in office A) and also distributed to B (in Office B via VPN), how does DFS know that it would be clever to use the file from A for a User in Office A and not from B? Same for the user in Office B of course, but you must have guessed as much.

I would very much appreciate if you could even help me to ask the right question – it must be obvious that I'm not too experienced in the server world but that again is owed to the budget; I hope to have some of your sympathy there…

Thanks!

Best Answer

Yes, DFS Replication (DFSR) will be your best way of synchronising folders between the two sites, however you will need to put some work and reading in or hire a consultant.

EDIT - Don't start there, start here: http://technet.microsoft.com/en-us/library/cc782417%28v=ws.10%29.aspx

Start here: http://technet.microsoft.com/en-gb/library/cc732863%28v=ws.10%29.aspx

That guide is for 2008, but the principles are broadly the same for 2003/08/12. (Incidentally, with Windows 2003 going out of support in less than a year I think you'd be mad to put effort into shuffling the servers about and reconfiguring the environment at this point.)

One of the very first things you'll need to do is grasp the fact that DFS Replication (DFSR) and DFS Namespaces (DFSN) are two completely different features, and can be utilised independently. You could, for example, use DFSR to replicate your folders, and have the clients at each site point direct to the share on the local server, without using DFSN.

If you are using domain-based DFS Namespaces, then you will point your clients to \\domain.local\Share and when the client accesses the share they will receive a 'referral' from a DC, which will point them towards server(s) that hosts a copy of the share. In order to get the client to go to the local or 'in-site' server, the referrals are costed based on the site of the clients and servers and the cost of the site links (Active Directory Sites).

It's not dark magic, but the actual requirements and mechanisms for fulfilling them are inherently complicated. There's plenty of documentation out there, so you'll just have to do a load of googling and set up a test environment, there's no easy way around that.