Question and feature requests for processor bound systems

Wayne Davison
Thu, 18 Aug 2005 18:34:06 -0000

On Thu, Aug 18, 2005 at 04:45:21AM -0500, Evan Harris
wrote:
> Is there any way to disable the checksum block search in rsync, or to
> somehow optimize it for systems that are processor-bound in addition
> to being network bound?

The --whole-file option (-W) disables the rsync algorithm entirely, but
not the full-file checksum to verify that the file was transferred
correctly.

> Option 1: Add an option, maybe --optimize-append, that would optimize
> the checksum search by telling it that it can assume that files are
> probably just appended to, like logfiles.

The CVS source (also available in the "nightly" tar files) has the
--append option that only transfers files that have gotten longer (or
are new), starting the transfer after all the existing data.  That
should save some checksum processing, but, rsync still includes all
the old data in the full-file checksum that verifies that the file
was sent correctly.

..wayne..