NOTE: These instructions are entirely untested. They may or may not work for you. Due to the number of possible drive configurations, there's no easy way for me to support drive speed optimization automatically. I may figure out how to do it eventually, but for now you're on your own.
After you've confirmed step 2, you can either choose a drive to erase or type "Q" to drop down to a shell. If you go to the shell, you can try some things to speed up disk performance, which could significantly reduce the amount of time it takes for Autoclave to run.
To see what your current disk performance is, run this command:
hdparm -Tt /dev/hda (or whatever /dev/hd* you're going to wipe) Run that a couple of times to get a good average.
Now fiddle with hdparm settings (see this article about hdparm) and test the speed again. For example:
hdparm -X66 -d1 -u1 -m16 -c3 /dev/hda
hdparm -Tt /dev/hda
If the write speed was faster, excellent. You can run autoclave now with the command:
If it was slower, go ahead and reboot to get it back to where it was.