I have a very large Maildir I am copying to a new machine (over 100BASE-T) with rsync. The progress is slow. VERY SLOW. Like 1 MB/s slow. I think this is because it is a lot of small files that are being read in an order that essentially is random with respect to where the blocks are stored on disk, causing a massive seek storm. I get similar results when trying to tar the directory. Is there a way to get rsync/tar to read in disk block order, or otherwise overcome this problem?
Edit: I tried tar cf /dev/zero Maildir/ and on the old system, this took 30 minutes! On the new system when the rsync finally finished, the same test took 18 minutes. Dumping the same directory on the old system took 8 minutes, and on the new system, dump -0f /dev/zero -b 1024 /home/psusi/Maildir/ finished in only 30 seconds.