#!/bin/bash
# Join 4 devices together
size1=`blockdev --getsize $1`
size2=`blockdev --getsize $2`
size3=`blockdev --getsize $3`
size4=`blockdev --getsize $4`
echo "0 $size1 linear $1 0
$size1  $size2 linear $2 0
$[$size1+$size2]        $size3 linear $3 0
$[$size1+$size2+$size3] $size4 linear $4 0" | dmsetup create joined