+GROOT=$($ROOTCMD grub-probe -tdrive -d $BOOT_DEVICE)
+
+# handle /boot in lvm-on-md
+_bdev=$(readlink -f $BOOT_DEVICE)
+if [ "${_bdev%%-*}" = "/dev/dm" ]; then
+ BOOT_DEVICE=$( lvs --noheadings -o devices $BOOT_DEVICE | sed -e 's/^*\([^(]*\)(.*$/\1/' )
+fi