I'm using the following command to copy a large number of big video files to external drives.
rsync -Ph --inplace /Volumes/Production/Prefix* Prefix
We had a power failure and the copying was abrupted. With rsync it's no problem to just restart it, but the thing is that it takes quite a while for it to get back to where it was. It goes through every file and looks like it reads through the whole file. Its speed is reported to be around 3-5 times faster than what it usually is, up to when it gets to the point it starts to copy again.
What is it doing exactly during this time? Is it reading through the whole file and comparing it with the source? Or is it doing something else fancy? Is there a way to get rsync to skip completed files faster? For example tell it to only check files that have a different file size or something?