[clue-tech] CLUE Talk Mailing list mbox file too big to rsynch

[David L. Anselmi]

Angelo Bertolli wrote:
> Normally rsync doesn't compare the two files:  it just compares the
> timestamps and sizes, then copies the whole file if they don't match.  You
> can force a comparison check, but that usually takes even longer.

I think you're confusing rsync's local operation with its networked 
operation.  When the source and destination are local it just copies. 
Over a network it uses its delta-transfer algorithm.

Think about it.  In order to calculate the delta to send rsync has to 
read both copies of a file.  On a single machine reading one copy and 
writing the other will be faster than reading both, calculating, and 
writing the differences.

On a sufficiently fast network (relative to disk and CPU speed), the 
rsync algorithm will be slower than a plain copy.  But I'm pretty sure 
the network between cluedenver and Jed is not that fast.

Dave