http://www.computerforums.org/forums/server-articles/how-setup-live-xenservers-backups-208663.html

• The CLEARDOWN.sh script reclaims disk space from deleted snapshots
• startvmbackup.sh is the script that will start the live backups of our XenServer VMs

mkdir /home/backup
mkdir /VM_Backup

# Use a command like this if you want to send backups to a CIFS share
#mount -t cifs "//192.168.0.20/VM_Backup" -o username=username,password=password /VM_Backup

cd /VM_Backup
wget http://www.andy-burton.co.uk/files/xenserver_backup/xenserver_backup.tar.gz
tar -xzf xenserver_backup.tar.gz
chmod 777 v*

vi /home/backup/startvmbackup.sh

#!/bin/bash
set -x

# Dismount then remount backup share to be sure it's mounted
umount -f /VM_Backup

#mount -t cifs "//192.168.0.20/VM_Backup" -o username=username,password=password /VM_Backup

/VM_Backup/CLEARDOWN.sh

/VM_Backup/vm_backup.sh

/VM_Backups/CLEARDOWN.sh

sleep 120

/VM_Backups/CLEARDOWN.sh

Edit the vm_backup.cfg file:

cd /VM_Backup
vi vm_backup.cfg

Insert these two lines in the Settings section:

#
# Settings
#

VM_XENHOST=$(xe vm-list | grep 'Control domain on host' | awk -F ': ' '{ print $3 }')

VM_XENUUID=$(xe vm-list params uuid=$(xe vm-list | grep -B1 $VM_XENHOST | grep uuid | awk -F ': ' '{ print $2 }') | grep resident-on | awk -F ': ' '{ print $2 }')

Set log path:

log_path="/VM_Backup/"$VM_XENHOST"/"$date".log"

Set the backup destination:

backup_dir="/VM_Backup/"$VM_XENHOST"/"

Ensure only running VMs are backed up:

backup_vms="running" 

Edit the vm_backup.lib file:

vi vm_backup.lib