Cleaning Disk

Some time ago I explained my procedure for initializing disks I plan to use in ZFS pool. And the first step was to fill them with random data from /dev/urandom.

However, FreeBSD /dev/urandom is not really the speed monster. If you need something faster but still really secure, you can go with a random AES stream.

Terminal  Copy
openssl enc -aes-128-ctr -pass pass:"$(dd if=/dev/urandom bs=128 count=1 2>/dev/null | hexdump)" \
    -pbkdf2 -nosalt </dev/zero | dd of=/dev/diskid/DISK-ID-123 bs=1M

Since the key is derived from random data, in theory it should be equally secure but (depending on CPU), multiple times faster than urandom.