rsync does not do the post-copy verification for local file copies. You can verify that it does not by using
rsync to copy a large file to a slow (i.e. USB) drive, and then copying the same file with
time rsync bigfile /mnt/usb/bigfile
time cp bigfile /mnt/usb/bigfile
Both commands take about the same amount of time, therefore
rsync cannot possibly be doing the checksum—since that would involve re-reading the destination file off the slow disk.
man page is unfortunately misleading about this. I also verified this with
strace—after the copy is complete,
rsync issues no
read() calls on the destination file, so it cannot be checksumming it. One more you can verify it is with something like
iotop: you see
rsync doing read and write simultaneously (copying from source to destination), then it exits. If it were verifying integrity, there would be a read-only phase.