Keep one BIG file in sync

Joseph Annino jannino at
Fri Feb 22 12:48:00 EST 2002

But I thought rsync will always copy the complete file, not just the
differences.  So the checksums are for the complete file, and if the
complete file checksum doesn't match, the complete file is transferred.
That isn't whats desired here, just the differences WITHIN a file.

If my understanding is wrong and rsync does have the proper magic to copy
just the differences within a file then rsync is even cooler than I thought.

On 2/21/02 8:30 PM, "Jason Haar" <Jason.Haar at> wrote:

> On Thu, Feb 21, 2002 at 07:27:20PM -0500, Joseph Annino wrote:
>> The big problem is when diffs are usually done, you need to compare every
>> bite in both files to find the deltas.  So in a network situation you
>> wouldn't save any effort because everything would have to go across the
>> network anyhow, so why not just copy the file?
> ?? That's exactly what rsync is designed to do. The rsync client does
> checksums on it's copy of the file, and the rsync server does checksums on
> it's copy - and then they use the network to send the checksums to each
> other. Until that happens, all I/O is local...
> BTW: if this is an Exchange server being talked about, NEVER, EVER, TOUCH AN
> I know: I did :-)
> [Apparently it's a feature...]

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