To clear a large hard drive I was using
dd if=/dev/zero of=/dev/sda. Only later I realized from reading more sources that the default block size is 512, and if I want the process to go quicker I should increase the block size to at least 4M.
My question is what happens if I cancel before it finishes (ctrl + c or quitting terminal would cancel it hopefully?). Am I able to redo the command and set a higher bs? Or would the system basically be corrupted at this point and I wouldn't even be able to log back in? If I can still redo it at this point, what would be the highest bs value I can use for a 1TB drive (software raid 1 if it matters)?