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Short version:

What software can I use to mirror data (files/folders) between two Windows servers across a broadband internet connection?

Longer version:

I'd like to implement an off-site backup solution for a company with two locations. Instead of transporting external drives to/from the locations or employee homes, I am interested in implementing a data mirroring solution that will use two servers to back each other up. The idea is that in the event of a physical catastrophe, one server should have the data for both locations.

Both servers will be running Windows Server 2008 or newer and both will have disks arranged in a RAID for local redundancy and drive failure protection.

I had encountered a software program at one time that was designed to accomplish this mirroring by limiting the bandwidth used on an internet connection during business hours, and doing the majority of data mirroring at night. The idea being that data is copied to the other server as soon as it is changed, but in such a way that bandwidth usage does not compromise business activities. Unfortunately I cannot remember nor find such a software program and am looking for advice from the ServerFault community.

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up vote 6 down vote accepted

The built-in tool to do this on Windows is called Distributed File System Replication (DFSR). It works well in many cases, and does have some ability to have a set schedule for when replication happens.

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This should also utilize the built-in Remote Differential Compression to minimize network load. – Scivitri Aug 3 '11 at 22:10

Two problems need two solutions.

  1. To copy/mirror the data you should use something simple as Robocopy from the Windows Resource Kit Tools.
  2. Doing QoS or bandwidth shaping is something your router/gateway should be able to manage. If not you need a appropriate gateway in between to do so.
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/IPG:n :: Inter-Packet Gap (ms), to free bandwidth on slow lines. /RH:hhmm-hhmm :: Run Hours - times when new copies may be started. /PF :: check run hours on a Per File (not per pass) basis. Can somewhat be replacements for the lack of QoS – Angel Aug 3 '11 at 23:10
@Angel thanks for pointing out these command line options - very useful! – JYelton Aug 4 '11 at 0:58

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