If you ever use the “dd” command do duplicate a drive, you’re probably familiar with the unnerving wait that accompanies its use. The command generally takes on the order of *minutes* to complete, and gives no feedback.
If you read the MAN page, you’ll see you can monitor the progress by sending a SIGINFO signal.
Open another terminal window, and do
kill -SIGINFO <dd pid>
Where <dd pid> is the process id of your dd command. For example, when I was formatting the SD card for use in my Raspberry Pi via dd on the command line, I was able to monitor progress this way:
sudo dd if=~/Downloads/2013-02-09-wheezy-raspbian.img of=/dev/disk2 bs=2048k 193+0 records in 192+0 records out 402653184 bytes transferred in 314.132226 secs (1281795 bytes/sec)
UPDATE: OMG! I just realized that the moment in time when I sampled my software installation on my Raspberry Pi was 100π to 4 digits of precision. What a wonderful omen!