[Raion]

Exercise never worked for me to zero out any data on the disk and takes way too long to actually do anything and in general I think it actually hurts the longevity of our drives. 

Instead, once you boot into the miniroot, go do admin, mkfs. Run mkfs. That will erase everything in the file system. The issue is if you run FX on a disk, I think it just modifies the partition table and doesn't actually format the underlying partitions so what happens is the miniroot sees that there's a valid file system and just uses it. 

Not sure if this works for older systems though.