You need to back up the files and the folders in the sh…

Your network contains a server named Server1 that runs Windows Server 2012.
Server1 is configured as a Hyper-V host.
Server1 hosts a virtual machine named VM1.
VM1 is configured as a file server that runs Windows Server 2012.
VM1 connects to a shared storage device by using the iSCSI Initiator.
You need to back up the files and the folders in the shared storage used by VM1.
The solution must ensure that open files are included in the backup.

What should you do?

A.
From Hyper-V Manager, create a snapshot of VM1.

B.
From Server1, perform a backup by using Windows Server Backup.

C.
From VM1, perform a backup by using Windows Server Backup.

D.
From Microsoft System Center 2012 Virtual Machine Manager (VMM), create a copy of VM1.

Explanation:
https://technet.microsoft.com/en-us/library/dn798286.aspx#BKMK_VM_B
Back up data from within the Virtual Machine when you need to backup data that is not supported by Hyper-V VSS… like iSCSI Storage.
certbase notes:
We can start Server Backup on VM1 and make a backup of the relevant user data Windows. The Volume Shadow Copy Service (VSS) allows besides, also the
fuse of files that are in use. The remaining solutions not lead to the goal. The user data are not on the Hyper-V host, but on an external storage device. The Creating
a Snapshots (apart from the fact, that a Snapshot never an alternative to a data backup represents) or backing up or Copy the virtual machine, closes the data of
the external memory not a.

Backing Up Hyper-V Virtual Machines Using Windows Server Backup

http://blogs.msdn.com/b/taylorb/archive/2008/08/20/backing-up-hyper-v-virtual-machines-using-windowsserver-backup.aspx