I believe the way it works is:

Rsync divides the file up into blocks and transfers only the blocks that
have changed.  Then it re-assembles the file on the receiving side using
the changed blocks (that were just transfered) and the unchanged blocks
(which already existed on the receiving side).

-Rob

Nick Smith wrote:
> Do you know how it does that? I thought it just checked checksums to
> see if they were different?  How can it just download the changes to a
> large DB like that if its all contained in a single file DB?
> 
> thanks
> 
> On Thu, Oct 9, 2008 at 3:38 PM, David Rees <drees76 AT gmail DOT com> wrote:
>> On Thu, Oct 9, 2008 at 11:06 AM, Nick Smith <nick.smith79 AT gmail DOT com> 
>> wrote:
>>> I am using the volume shadow copy to backup large (12gig+) sql db's.
>>> After the first full backup, and things are changed/added to the DB,
>>> is it going to pull down the entire DB again or will it just download
>>> the changes
>>> (if thats possible)
>> As long as the file names remain the same and you are using rsync,
>> only the changes will be downloaded.
>>
>> -Dave
>>
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> 
> 
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