Change memory size for a running Virtual Box virtual machine

ChangeVBMem.sh

#!/bin/bash          

#
#  ChangeVBMem.sh
#
#	ver 1.0
#
#	Jose Gomez Castaño jgcasta@gmail.com
# 
#	Change memory size for a running virtual machine. The system will be stopped and restarted
#	In this version, all data has to be saved before 
#
#	nameVB: Virtual Machine name
#	newSize: RAM size in MB
#
#	Usage: $./ChangeVBMem.sh nameVB newSize
#

name=$1
newSize=$2

totalMem=$(free | awk '/^Mem:/{print $2}')
totalMemM=$((totalMem/1000))

if [ $totalMemM -lt $newSize ];then
	echo "ERROR: The maximum memory size of your physical machine is "$totalMemM" Mb and you are choosing "$newSize" Mb, please choose a lower value for the virtual machine"
	exit 0
fi

VBoxManage controlvm $name poweroff
VBoxManage modifyvm $name --memory $newSize
VBoxManage startvm $name