--csum-length ?!

jw schultz jw at pegasys.ws
Fri May 16 10:11:31 EST 2003

On Thu, May 15, 2003 at 04:51:36PM +0200, Paul Slootman wrote:
> >From the manpage:
> --csum-length=LENGTH
>         By  default  the primary checksum used in rsync is a very strong
>         16 byte MD4 checksum. In most cases you will find that  a  trun-
>         cated version of this checksum is quite efficient, and this will
>         decrease the size of the checksum data sent over the link,  mak-
>         ing things faster.
>         You  can  choose  the  number of bytes in the truncated checksum
>         using the --csum-length option. Any value less than or equal  to
>         16 is valid.
>         Note that if you use this option then you run the risk of ending
>         up with an incorrect target file. The risk with a value of 16 is
>         microscopic  and can be safely ignored (the universe will proba-
>         bly end before it fails) but with smaller  values  the  risk  is
>         higher.
>         Current versions of rsync actually use an adaptive algorithm for
>         the checksum length by default, using a 16 byte file checksum to
>         determine  if  a 2nd pass is required with a longer block check-
>         sum. Only use this option if you have read the source  code  and
>         know what you are doing.
> Of course, if you've read the source code, you'd know that there's no
> such option :-) So, I request that this be removed from the manpage.

If you were looking at CVS you'd know it already has.

	J.W. Schultz            Pegasystems Technologies
	email address:		jw at pegasys.ws

		Remember Cernan and Schmitt

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