paul at debian.org
Fri May 16 00:51:36 EST 2003
>From the manpage:
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
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.
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