For maximum compatibility and redudancy; mirrored vdev

is now always used for boot pool

Signed-off-by: Maurice Zhou <jasper@apvc.uk>

docs/Getting Started/Arch Linux/Root on ZFS/2-system-installation.rst

@@ -43,6 +43,9 @@ System Installation
 
 #. Create boot pool::
 
+    disk_num=0; for i in $DISK; do disk_num=$(( $disk_num + 1 )); done
+    if [ $disk_num -gt 1 ]; then INST_VDEV_BPOOL=mirror; fi
+
     zpool create \
         -o compatibility=grub2 \
         -o ashift=12 \
@@ -57,7 +60,7 @@ System Installation
         -O mountpoint=/boot \
         -R /mnt \
         bpool_$INST_UUID \
-        $INST_VDEV \
+         $INST_VDEV_BPOOL \
         $(for i in ${DISK}; do
            printf "$i-part2 ";
           done)