Lars Karlslund writes: > Also the numbers speak for themselves, as the --whole-file option is > *way* faster than the block-copy method on our setup.
At the risk of jumping into the middle of this thread without remembering everything that was discussed... Remember that by default rsync writes a new file and then renames that file. So a single byte change to a file requires a complete read and write (plus the earlier read to generate the block checksums). The --inplace option is more efficient in terms of disk IO, but the drawback is that blocks earlier in the original file cannot be matched. I haven't looked at the code, but I'm guessing --inplace still does byte-by-byte matching. An additional optimization for --inplace would be to only try to match on multiples of the block size. Also, the matching only proceeds byte-by-byte when there is no match. Once a match is found then the entire block is skipped. So on a file with few changes, the byte-by-byte matching doesn't slow things down very much. Craig -- To unsubscribe or change options: https://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html