I found myself in a situation I am copying an entire filesystem across two different HD partitions (different sizes and filesystem types). The problem so far is taht both
rsync will read a single file at the source, and write it on the destination - doing that for every small file. Therefore, I have only some small OS buffering and the HD cache itself to prevent the HD head to move back and forth for each small file - but it feels it is quite close to that.
The machine is got plenty of RAM. What could I do to say, read several megabytes (or even GB) worth of data on the same partition before comiting that on the other partition?
If it matters I am copying from BTRFS to EXt4 - data includes several git trees, source files and such (few large video and audio files).