I'm trying to synchronize a large local directory (with a batch file using rsync 3.0.7 on Cygwin, Windows 7 x64, 30k files, 200gb size) to a remote server (Debian x64 with kernel 2.6, rsyncd 3.0.7) over a slow internet connection (90kbyte/s upload).

I know almost all files are identical and I verified that using md5sum locally and remotely.

However when executing rsync from my local machine every file gets transferred completely for the first time. When I terminate the batch file after a few transfers and run it again then the already transferred files are skipped. But as soon as it gets to a file not yet transferred it uploads the file as a whole again instead of noticing that the checksum is the same locally and remotely.

The batch file calling rsync looks like this (backslashes and line brakes added here for readability):

c:\cygwin\bin\rsync.exe --verbose --human-readable --progress --stats \
    --recursive --ignore-times --password-file pwd.txt \
    /cygdrive/d/ftp/data/ \
    rsync://[email protected]:33400/data/  |  \
    c:\cygwin\bin\tee.exe --append rsync.log

I experimented using the following parameters in varying combinations but that didn't help either:

--checksum --partial --partial-dir=/tmp/.rsync-partial --compress