GetDevice.ps1

Function Get-Device() {            
    param(            
              [parameter (mandatory=$true)][string] $InstanceId            
          )            
    $CurrentDevice = Get-EC2InstanceAttribute $InstanceId -Attribute blockDeviceMapping | Select-Object -ExpandProperty BlockDeviceMappings | Select-Object -last 1            
If ($CurrentDevice.DeviceName -eq '/dev/sda1') {            
    $NewDevice = 'xvdf'            
    return $NewDevice            
}            
Else {            
    $a = $CurrentDevice.DeviceName.ToCharArray()            
    $inc = +1            
    $a[3] = [char]([int]($a[3])+$inc)            
    $NewDevice = -join $a            
    return $NewDevice            
    }            
}