But in copying real files, there's alot more going on that file I/O...
and that's where rysnc spends most of its time.
If file-I/O dominates, and not much data to xfer, rsync is a win, but if
data to
xfer is 'full' .. rsync will always be notably slower.
(as you note below...though it's worse
Direct I/O (assuming you mean O_DIRECT on open) can be a bit fiddly, but I
doubt it's out of reach. The main difficulty is allocating a buffer with
appropriate alignment.
I put together a library to facilitate O_DIRECT I/O a while back:
http://stromberg.dnsalias.org/~dstromberg/odirect/
odirect
As far as I can tell rsync doesn't support this. How hard would it be
to implement this? Is it trivial enough to just change the calls in the
code with sed? I think this can significantly reduce CPU usage and
increase I/O speed when dealing with fast storage solutions. It can make
a huge diffe
