On Tue, Nov 12, 2002 at 04:32:31PM +0100, [EMAIL PROTECTED] wrote: > I'd call it a bug.
No, it's not a bug. It's the heart of the rsync algorithm at work. Rsync trades CPU and local file I/O for network I/O in order to reduce the amount of data that is transferred over the network. Your diagnosis has just shown that when the network I/O dips, rsync has traded it for local I/O (grabbing matching blocks from the current file instead of asking for it to be sent over the network). For really large files that have most matching data, most of the file I/O in building a new file will not be network I/O, so it is to be expected that the data rate over the net will drop when that occurs. Note also that the --partial flag is only incidentally related to what you were seeing since it ensured that the destination file had lots of matching data whenever you interrupted the transfer. The only alternative is to use the --whole-file option -- this option turns off the rsync algorithm and just sends all the changed files over the net completely (like an scp copy, but for changed files). This should only be used if you have a really fast network connection OR if you don't want to trade the CPU and local I/O for network I/O. ..wayne.. -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.tuxedo.org/~esr/faqs/smart-questions.html
