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.
