Moving changes of a large file over Internet

[abusam]

Hello, I have the same 4GB file located at two sites connected via vpn, everyday people at the first site make minor changes doesn't exceed 1 or 2 MB, I've been looking for a method to transfer the change only other than copying the whole file to the second site.

I thought rsync would do that, but it turned out even rsync copy the entire file if it's changed on the destination place. Any ideas ?

Thanks

[HROAdmin26]

The rdiff-backup utility is one option. You can of course script a solution that uses diff and rsync.

[abusam]

Thank you very much, does it work with binary files ?

[sileryti]

yes, it does, here's a quote from their "features" document:

"Space efficient: Suppose you have a large database file that changes a little bit every day. A normal incremental backup would keep saving copy after copy of this database, wasting a lot of space. rdiff-backup uses librsync, which implements the same efficient diffing algorithm that rsync uses. It works on binary files as well as text, so only a fraction of the data in your database would be saved in each incremental backup."