rsync Not Immediately Showing Progress

When I run a rsync command on an Ubuntu 20.04 machine to transfer some files to a WSL1 system running on a Windows 10 machine, the transfer progress is not always shown immediately despite using the -P.

rsync --bwlimit=200000 --remove-source-files -P /data/*.dat rsync://elonmusk@192.168.1.2:12000/data

It sometimes takes about 5 minutes before showing the progress details

382abd067bf4bddc701db2dc8da67656368b7a6b58f6abd60cfada3e3499ca6f.dat 78,138,310,656 71% 292.50MB/s 0:01:42 

Is there a way to force rsync to always show the progress soon after starting the transfer? Using rsync version 3.1.3 on the Ubuntu system.

1 Answer

I would assume that you're copying files with a name matching files on the destination. In this instance the delay is related to rsync checksumming the source and destination to see what, if anything, has changed. The progress indicator shows the transfer of data.

If you include timestamps in the copy you may find that rsync doesn't need to perform the copy at all. (Unless the data has changed, of course).

rsync --bwlimit=200000 --remove-source-files -tP /data/*.dat rsync://elonmusk@192.168.1.2:12000/data/