Wojtek.Pilorz wrote: > On Thu, 12 Apr 2007, John R Pierce wrote: >> Dale Sykora wrote: >>> I know of a few techniques for minimizing server bandwidth when >>> bittorent is not an option. >>> >>> 1) If you have the beta isos, you can rename them as centos 5 isos and >>> then rsync from a mirror that allows rsync (such as kernel.org). Then >>> only changes from beta to centos 5 plus some overhead is downloaded. I >>> suppose you could use this technique with bittorrent too. >>> >> if one file near the beginning of the ISO changes size by even a block, >> then the whole rest of the ISO will be different, this will gain you >> nothing. > With bittorrent, that is perhaps true. > Rsync will be able to handle that difference. But if most RPMs are rebuild > that it will have not much matching data. By way of example, I had a recent daily build of Debian Etch (mid March). When Debian released (must be a blue moon!) earlier this week, I rsynced the three DVD images. rsync did it really quickly, and claimed over 1 mbyte/sec on an ADSL 256k incoming link. Another example; a few years ago I had a broken ISO that rsync would not fix, it was the same size and timestamp as the original, and checksumming was forbidden. I pruned a little off by copying about 1k less with dd, then rsync did fix it. (wonders why touch didn't work. hmm.) -- Cheers John -- spambait 1aaaaaaa at coco.merseine.nu Z1aaaaaaa at coco.merseine.nu Please do not reply off-list