I've just subscribed, but a search of the archive doesn't indicate this has been handled before...
Is there a way to get rsync to not create a new file while transferring and then rename it, but to instead update the existing file in place, i.e. simply write those blocks that have been updated and leave the rest alone? That would be ideal for what I wanted rsync for, namely updating copies of Oracle data files. These reside on a volume of a NetApp Filer where other stuff is also located, and snapshots are made regularly of that volume. Simply deleting the old files and copying them again means that the Filer considers each and every block of the old files "old", and that mens they get preserved in the snapshots, which in turn means that the snapshots take up WAY too much space (the snapshots are a sort of "copy-on-write" mechanism: as long as only a few blocks are updated, you only need a few blocks to maintain a snapshot). I thought that I could get around this by using rsync, because of the way it only transfers those blocks that have changed. I now know a bit more about how it works :-) In no way does rsync increase disk IO efficiency, it increases network IO efficiency... That of course is fine, but unfortunatley not quite suited to the purpose I had in mind. How difficult would it be to add an option so that it works in the way I would want? I understand that it would mean losing the "moved data" optimization, but for Oracle data files where relatively little is updated (and probably not moved at all) that wouldn't matter a whole lot. (The set of files I'm talking about is 40GB in about 20 files, with 4 files of 8GB.) In the meantime I'll probably hack up something that compares two files and then updates those blocks in the second file that differ... won't work over a network though :-) Thanks, Paul Slootman -- -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.tuxedo.org/~esr/faqs/smart-questions.html
