bhyve question about vm-bhyve create zvol vm in freebsd15 ?

[fff2024g]

dear all:
i have create a freebsd15 server with 2 zpools (system2026 for freebsd system, vmdata for vm-bhyve vm ). below was the configure ..

Script started on Fri Apr 10 11:36:36 2026
root@yjjy002:~ # zpool lis
zpool list
NAME SIZE ALLOC FREE CKPOINT EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT
system2026 764G 6.54G 757G - - 0% 0% 1.00x ONLINE -
vmdata 7.27T 3.84G 7.26T - - 0% 0% 1.00x ONLINE -

#zpool status
pool: system2026
state: ONLINE
config:

NAME STATE READ WRITE CKSUM
system2026 ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
da0p3 ONLINE 0 0 0
da1p3 ONLINE 0 0 0

errors: No known data errors

pool: vmdata
state: ONLINE
config:

NAME STATE READ WRITE CKSUM
vmdata ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
da2 ONLINE 0 0 0
da3 ONLINE 0 0 0

errors: No known data errors
root@yjjy002:~ # zfs list
NAME USED AVAIL REFER MOUNTPOINT
system2026 6.54G 734G 96K /system2026
system2026/ROOT 6.54G 734G 96K none
system2026/ROOT/default 6.54G 734G 6.54G /
system2026/home 96K 734G 96K /home
system2026/tmp 104K 734G 104K /tmp
system2026/usr 288K 734G 96K /usr
system2026/usr/ports 96K 734G 96K /usr/ports
system2026/usr/src 96K 734G 96K /usr/src
system2026/var 788K 734G 96K /var
system2026/var/audit 96K 734G 96K /var/audit
system2026/var/crash 96K 734G 96K /var/crash
system2026/var/log 300K 734G 300K /var/log
system2026/var/mail 104K 734G 104K /var/mail
system2026/var/tmp 96K 734G 96K /var/tmp
vmdata 3.84G 7.14T 96K /vmdata
vmdata/vm 3.84G 7.14T 248K /vmdata/vm
vmdata/vm/fb15 238M 7.14T 120K /vmdata/vm/fb15
vmdata/vm/fb15/disk0 237M 7.14T 236M -
vmdata/vm/fb16 1.30M 7.14T 112K /vmdata/vm/fb16
vmdata/vm/fb16/disk0 1.23M 7.14T 236M -
vmdata/vm/hlw001 1.80G 7.14T 1.80G /vmdata/vm/hlw001
vmdata/vm/hlw002 11.2M 7.14T 1.79G /vmdata/vm/hlw002
vmdata/vm/hlw003 1.79G 7.14T 1.79G /vmdata/vm/hlw003

root@yjjy002:~ # cat /tc/rc.conf
hostname="yjjy002.laifeng.xian"
ifconfig_igb0="inet 10.8.1.253 netmask 255.255.255.0"
defaultrouter="10.8.1.254"
sshd_enable="YES"
moused_nondefault_enable="NO"
# Set dumpdev to "AUTO" to enable crash dumps, "NO" to disable
dumpdev="AUTO"
zfs_enable="YES"
vm_enable="yes"
vm_dir="zfs:vmdata/vm"

root@yjjy002:~ # vm switch list
NAME TYPE IFACE ADDRESS PRIVATE MTU VLAN PORTS
public standard vm-public - no - - igb0

root@yjjy002:~ # vm list
NAME DATASTORE LOADER CPU MEMORY VNC AUTO STATE
fb15 default bhyveload 1 2gb - No Stopped
fb16 default bhyveload 1 2gb - No Stopped
hlw001 default uefi 8 32gb 10.8.1.253:5900 No Running (6308)
hlw002 default uefi 8 32gb 10.8.1.253:5901 No Running (6854)
hlw003 default uefi 8 16gb 10.8.1.253:5902 No Running (7246)
root@yjjy002:~ # exit

question was in below picture ...when i used command : # vm create -t freebsd-zvol -m 2gb -s 20gb freebsd15 . ..got a error message in the picture. please help me. thanks.....