If you're wiping disks from the command line (which I do when doing full disk wipes), just use dd, and control-t to tell where it is. It won't give you a pretty percent done, or time remaining, but you can see how many bytes it's wiped, and roughly calculate from there. I never bother sending signals with kill(all). Control-T is easier. If I'm not at the ssh session to press control-T, then I probably don't care too much about a progress update.