#!/bin/bash
# Backup of Xen VM's
# Tiago Cruz - tiagocruz@everlinux.com
# v 1.0	Mar/2008 - Initial version, just backup all VM's
# v 1.1 May/2008 - Now we have functions and parameters

export PATH=$PATH:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
BACK="_snap"
LOG=/var/log/backup.`date +%Y%m%d`
# root partition to backup ("/")
# usually the second it's swap
ROOT="1"

[ ! -d "/mnt/back" ] &&  mkdir -p /mnt/back
[ ! -d "/data/backup" ] &&  mkdir -p /data/backup

function showHelp() {
        echo " "        
        echo "Use the following parameters: "
        echo "          help   = Show this help"
        echo "          all    = Backup of all VM's"
        echo "          list   = List all VM's from this domain"
        echo "          <vm>   = Backup one specific VM"
        echo " "
	echo "ex: back_xen.sh tomcat_shop"
        echo " "
	exit 1
}

function listVM() {
	echo "List of VM's avaliables:"
	/usr/sbin/xm list | awk '{print $1}' | egrep -v '(Name|Domain-0)'
	echo " "
}

function backXen () {
	echo "Backuping machine $i..."
	echo "Please, look the progress on $LOG"
	listVM | grep $i >/dev/null
	if [ $? -ne 0 ]; then
		echo "Machine $i does not exist, aborting!"
		exit 2
	fi	
	backup
	if [ $? -eq 0 ]; then
                echo "Backup of $i completed successfully!!!"
		echo "Backup finalized on `date` with load `cat /proc/loadavg | cut -c 1-14`" >> $LOG
		echo "=====================================================================================================" >> $LOG
		echo "=====================================================================================================" >> $LOG
        fi
}

function backAll () {
	VMS=`xm list | awk '{print $1}' | egrep -v '(Name|Domain-0)'`
	for i in $VMS; do
		backup
	done
	echo "Backup finalized on `date` with load `cat /proc/loadavg | cut -c 1-14`" >> $LOG
	echo "=====================================================================================================" >> $LOG
	echo "=====================================================================================================" >> $LOG
}

function backup () {
	echo "=====================================================================================================" >> $LOG
	echo "Backup $i started on `date` with load `cat /proc/loadavg | cut -c 1-14`" >> $LOG
	DEVICE=`grep ^disk /etc/xen/$i | awk -F "Vol_LVM" '{print $2}' | cut -d / -f 2 | cut -d , -f 1`
	echo "Virtual Machine $i uses $DEVICE as storage device" >> $LOG

	lvcreate --snapshot -L 15G -n $i$BACK /dev/Vol_LVM/$DEVICE >> $LOG 2>&1
	[ $? -ne 0 ] && echo "Error $i: creating LVM $i$BACK" >> $LOG 

	kpartx -a /dev/mapper/Vol_LVM-$i$BACK >> $LOG 2>&1
	mount /dev/mapper/Vol_LVM-$i$BACK$ROOT /mnt/back/ >> $LOG 2>&1
	[ $? -ne 0 ] && echo "Error $i: mounting $i$BACK$ROOT" >> $LOG 

	SIZE1=`df -hP /mnt/back/ | awk '{print $3}' | grep -v Used`
	SIZE2=`df -hP /mnt/back/ | awk '{print $2}' | grep -v Size`
	echo "Backup of /dev/mapper/Vol_LVM-$i$BACK$ROOT - $SIZE1 of $SIZE2 used" >> $LOG
	tar zcf /data/backup/$i-xen.tar.gz /mnt/back >> $LOG
	[ $? -ne 0 ] && echo "Error $i: creating /LVM/backup/$i.tar.gz" >> $LOG 
	
	SIZE3=`ls -lh /LVM/backup/$i-xen.tar.gz  | awk '{print $5}'`
	echo "Created /LVM/backup/$i-xen.tar.gz with $SIZE3" >> $LOG

	sleep 1
	umount /mnt/back/ >> $LOG 2>&1
	[ $? -ne 0 ] && echo "Error $i: umounting $i$BACK" >> $LOG 
	kpartx -d /dev/mapper/Vol_LVM-$i$BACK >> $LOG 2>&1
	[ $? -ne 0 ] && echo "Error $i: deleting partition mappings $i$BACK" >> $LOG 
	
	echo "Removing snapshot already backuped $i$BACK" >> $LOG
	lvremove /dev/Vol_LVM/$i$BACK -f >> $LOG 2>&1
}

if [ "$#" -eq 0 ]; then
	showHelp

fi

case "$1" in 
	list)	listVM	;;
	all )	backAll	;;
	help)	showHelp ;;
	 *  )  	i=$1; backXen ;;
esac