Goal: synch a large number of large files (filesize>500MB) from one NAS (WD Mycloud) to another. rysnc is available on both. Both are connected via a Gigabit switch. NAS files can be moved with Windows Explorer at 40+MB/s, however the file metadata (dates) are changed to the current date. rsync runs at ~10-12MB/s.
I initially mounted source via CIFS, but I was informed this could be a bottleneck, so I ditched CIFS and tried to turn off compression:
rsync -aHXxvn --numeric-ids --delete --progress -e "ssh -T -c arcfour -o Compression=no -x" email@example.com:/shares/public/Data /shares/public/
This command originated from this article, which I think indicates the command would optimize SSH overhead
I didn't observe any speed increase. What test can be performed to diagnose the bottleneck preventing 40MB/s transfers?