If you are looking to do snapshot based VM backups in a XenServer environment then check out this collection of scripts:
VBScript method
Perl script method
Andy Burton’s XenServer bash script
Location
Deptive - Commercial Bay
11-19 Customs Street West St
Commercial Bay Tower, Level 17, Room 1715
Auckland 1010
Contact Details
0800 000 141
Postal Address
PO Box 34797,
Birkenhead, Auckland 0746