/dev/urandom is too slow to fill a drive

I can never remember how to use OpenSSL to generate randomly seeded garbage. Thankfully, there’s a post on netzgewitter.com:

Speed wiping a hard drive with crypto garbage generated by openssl

Update: netzgewitter.com seems to be down. Here’s the important bit:

$ openssl enc -aes-256-ctr -pass pass:"$(dd if=/dev/urandom bs=128 count=1 2>/dev/null | base64)" -nosalt </dev/zero > /dev/sda

replace /dev/sda with the block device you wish to erase