How do you backup virtual machines in Microsoft Hyper-V Server?

Question

Microsoft

What and how do you back up virtual machines running Microsoft Hyper-V Server?

Answer 1

In 2008 - using diskshadow and robocopy
In 2012 - using built-in Hyper-V replica

Answer 2

built-in hyper

Answer 3

Symantec Backup Exec. Paid, expensive thing, but [subjectively] quite convenient.