--itemize-changes not recursive (not printing created files inside created directories)

Paul Slootman paul+rsync at wurtel.net
Wed Dec 18 14:10:02 MST 2013


On Wed 18 Dec 2013, Kevin Korb wrote:

> Also, rsync's -c is rather dumb as it computes checksums for files
> that have different sizes so they can't possibly be the same and it
> computes checksums for files that only exist on one end and therefore
> has nothing to compare them to.

The list of files on the source is generated and transferred to the
destination before rsync knows that the destination file is different.

To make rsync checksum only the files with same size would mean changing
the filesystem scan to a two-pass thing (send the list of filenames plus
their sizes, wait for the destination to tell you what files need
checksumming, do that and send the filenames again, now with checksum
data), and retransferring file metadata again. Remember that rsync is
basically a tool optimized for very fast local IO and much lower network
bandwidth, so such a two-pass feature could possibly greatly increase
the network traffic overhead (i.e. traffic not related to file data
itself).

That said, I'm sure that if someone builds a patch to implement
something like that via yet another commandline option, no one would
complain :-)


Note that transferred files are always checksummed anyway, as
described at the end of the -c option manpage description.


Paul


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