I'm trying to setup a file sync between the file server at my house and the one at my brother's so that we each have offsite backups of important data. Both systems are running Windows (XP on one, 7 on the other).
I like the fact that rsync will only transfer part of a file, the part that has changed, and not the whole thing...saving a lot of bandwidth. But I have had very little luck getting it to work properly. I tried using DeltaCopy, but it's interface is horrible, and while it will work within my LAN it always fails to connect when remote. (See this question for more details on that)

Is there another alternative program that runs on windows and has similar functionality? So far the only other option I can see is using FTP and something like SyncBackPro...but that is just going to transfer the whole file...and only having 512kbps upload bandwidth makes that a total pain.

Edit: To clarify some more, the backup I'm doing needs to scan several hundreds of thousands of files, adding up to more than 400GB, on each end... which is why I'm not using an intermediary service like LIVE for the transfer...

Edit 2: Also, these backups need to be preformed over a remote connection and without a VPN... Meaning that using Windows File Shares (SMB) is out of the question...

  • 512 kb/s? Wow... And you're in the US?
    – alex
    Nov 12, 2009 at 14:05
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    I live in Romania and have 30 Mb/s download and 4 Mb/s upload for about 10$. Having 512 kb/s should be unacceptable.
    – alex
    Nov 12, 2009 at 14:34
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    haha...5Mb/s down and 512kb/s up and I pay $60 for it...welcome to the land of the free :D
    – Adam Haile
    Nov 12, 2009 at 14:54
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9 Answers 9


There is cwrsync which will let you run rsync in windows. We use it on one of our servers to back up about 140k files. FTP just couldn't handle that.


rsync does work on windows - deltacopy is a wrapper around it - though you can use the rsync packaged in it on its own.

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    I like this a bit better than cwrsync as it seems slightly more "Windows-ified" - ultimately they do exactly the same thing.
    – Goyuix
    Nov 12, 2009 at 15:33
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    If using this rsync, be aware that it expects cygwin paths.. e.g. /cygdrive/c/users/
    – jnnnnn
    Oct 27, 2012 at 6:43

rdiff-backup uses the rsync algorithms for transmitting only file differences and it keeps file history. The history part is could be a very important feature for your backup scheme.

I have been using in around the (microsoft only) office for over a year. It just works.

  • Interesting find.
    – Nicholi
    Jul 26, 2011 at 19:03

I would suggest you give Robocopy a shot. It's part of Vista/7/2008 by default and in the newer version has mirror support. It also supports resume and networking shares.

  • Any way to get this to work over something other than a windows file share?
    – Adam Haile
    Nov 12, 2009 at 14:55
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    If you have large files that often have small changes robocopy is very network inefficient. It transmits the entire file even if only the last few bytes have changed. Nov 12, 2009 at 15:17
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    If rschuler is right, then Robocopy is nothing like rsync, and this is a bad answer. Nov 12, 2009 at 17:42
  • Robocopy was less than half the speed in a 4 GB download on the same line compared to other options. It couldn't resume broken transfers. My first impression is that it's overrated. Since then I found better tools but don't have enough experience to comment on those here. I did use Deltacopy and it was pretty cool. See another answer on it in this thread.
    – LMSingh
    Aug 14, 2015 at 0:10
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    Since it's a default package in Windows, it's useful in corporate environment where you do not have the permission to install any third party software on the systems(At least without going through a long chain of processes before you're allowed to install it).
    – 7_R3X
    Oct 10, 2017 at 7:54

I like Unison File Synchronizer...if you don't mind using commandline tools. It is fast, it scans files for changes much quicker than rsync. Similar to rsync, it only transfers changed portions of files.


Beginning with Windows Vista, the Offline files feature (also known as Client-Side Caching) will automatically sync over slow connections and only transfer the changed portions of files (much like rsync).

I mention this as a possible solution, although you specifically mention that SMB is not an option for you. If you were to give the systems routable addresses (such as IPv6 addresses), you could probably connect over the Internet without a VPN. I do this regularly, and it works well when the ISP isn't blocking the SMB ports. I wouldn't necessarily recommend this for you because one client is running XP, and your ISPs may be blocking SMB. Still, I wanted to mention that the capability is built into Windows Vista/7 when the connectivity is available.


You can use Windows Live Mesh. There's an option in Mesh that enables you to sync between machines, bypassing Live Desktop and its quota. So you can sync as much info as you want. It's simple to do this: on a folder that's Mesh enabled, choose Sync Settings > Live Desktop > select "Never with this device.".

That setting will skip syncing data with Live and sync directly between devices in your Mesh.

  • 1
    Mesh rocks. Seriously. Nov 12, 2009 at 15:42
  • With this method are there still limitations like file size, number of files in a directory, etc? This would be a dealbreaker for me...
    – Adam Haile
    Nov 12, 2009 at 18:43
  • Adam: Here are some limit numbers from over a year ago. Not sure if there are changes since this was published: blogs.msdn.com/livemesh/archive/2008/08/13/…
    – Sajee
    Nov 13, 2009 at 3:29

You could install cygwin (http://www.cygwin.com) on both machines, install an ssh server on the remote machine (such as cygwin's, or perhaps http://sshwindows.sourceforge.net/), and then use rsync on Windows.


BackupPC is an open source backup solution that uses rsync amongst other things. I think this may do what you want.

Alternatively, there is always Windows Live Sync. It is a very simple and robust way to sync Windows and Macs, but with the following limits:

A maximum of 20 folders (or "libraries") may by synced, including libraries shared over the internet. Each library can contain a maximum of 20,000 files and each file cannot exceed 4GB.

If what you want to sync fits in those parameters, give it a go.

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