1. Login via SSH, execute commands below. 2. sysctl kern.geom.debugflags=0x10 3. dd if=/dev/zero of=/dev/ada4 bs=512 count=1 && dd if=/dev/zero of=/dev/ada5 bs=512 count=1 4. Log into web interface and use “View Disks” to wipe the drives in that interface 5. Create new ZFS volume including these disks.