I recently used dd to zero out some hard drives on my Fedora Core workstation, and found that this operation takes a good deal of time (even when large blocksizes are used, it still takes a while). The dd utility doesn’t report status information by default, but when fed a SIGUSR1 signal it will dump the status of the current operation:
dd if=/dev/zero of=/dev/hda1 bs=512 &
kill -SIGUSR1 1749
1038465+0 records in 1038465+0 records out 531694080 bytes (532 MB) copied, 11.6338 seconds, 45.7 MB/s
It still amazes me how much stuff I have left to learn about the utilities I use daily.