On #FreeBSD 14 yesterday I tried to do mock up #ZFS RAIDZ2 configuration via #mdconfig(8) of 20 TB "disks":

# As root in zsh.
for i in $( jot 14 )
do
file=$( printf "./md-%02d" $i )
touch "$file" \
&& mdconfig -a -s 20t -t vnode -o noreserve "$file"
done

zpool-create(8) fails:

zpool create Mock2 \
raidz2 $PWD/md-0[1-7] \
raidz2 $PWD/md-0[89] $PWD/md-1[0-4]
internal error: out of memory

Did I miss something?

# Free resources.
mdconfig -l | xargs -n 1 mdconfig -d -u
rm -f ./md-??