What are the chances of running mkfs on the wrong partition and tape drive chewing up your latest backup? 1 to a mil? Well, I got that today.
Luckily my /home was on a different filesystem and was not affected. I preffered a fresh install to the tape magic. With the proper kickstart took me less then 10 minutes over a 100Mbps network. Few misconfigurations caused few small problems like a couple of hundred of undelivery reports from my mailer, and the like.