FreeBSD Handbook confusion

I am new to virtualization and zfs.

Could someone re-write 23.6.2. Creating a FreeBSD Guest
Create a file to use as the virtual disk for the guest machine. Specify 
the size and name of the virtual
disk:
# truncate -s 16G guest.img

to use zfs instead of ufs?

I read 23.6.6. Using ZFS with bhyve Guests
If ZFS is available on the host machine, using ZFS volumes instead of 
disk image files can provide
significant performance benefits for the guest VMs. A ZFS volume can be 
created by:
# zfs create -V16G -o volmode=dev zroot/linuxdisk0
When starting the VM, specify the ZFS volume as the disk drive:
# bhyve -A -H -P -s 0:0,hostbridge -s 1:0,lpc -s 2:0,virtio-net,tap0 
-s3:0,virtio
-blk,/dev/zvol/zroot/linuxdisk0 \
-l com1,stdio -c 4 -m 1024M linuxguest

but can't correlate it.

It looks like these two sections were written by different people.

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FreeBSD freebsd.friedrich.org 13.2-RELEASE FreeBSD 13.2-RELEASE releng/13.2-n254617-525ecfdad597 GENERIC amd64