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Online VM Backups (Microsoft Hyper-V)

Updated

You can keep a virtual machine online while performing a backup.

For virtual machines running on a Hyper-V Server 2012 R2 host, online backups do not require any special configuration.

For best results with all host operating systems, ensure that integration services are up to date on the virtual machines. Integration services are required to perform application consistent backups.

Requirements for Online Backups with Hyper-V 2008 R2 or 2012 Hosts

Note

Applies only to Microsoft Hyper-V 2012 R2.

For virtual machines running on older operating versions of Hyper-V, ensure that the virtual machines meet the following requirements before performing the backup:

  • Integration services are installed and the backup integration service has not been disabled.

  • Integration services on the guest virtual machine must be set to the same level as the host Hyper-V server.

  • All disks used by the virtual machine are configured within the guest operating system as NTFS-formatted basic disks.

    Virtual machines that use storage on which the physical partitions have been formatted as dynamic disks or the FAT32 file system prevent an online backup from being performed. This is not the same as dynamically expanding virtual hard disks, which are fully supported by backup and restore operations.

  • Volume Shadow Copy Service must be enabled for all volumes used by the virtual machine. Each volume must also serve as the storage location for shadow copies of the volume. Ensure that the sufficient space, required for the snapshot creation, is available on each guest volume inside the virtual machine.

  • The configuration files for the virtual machine are stored with the Virtual Hard Drive (VHD) files on the host. This will ensure that the virtual machine does not go into the saved state during the snapshot creation.

  • In Hyper-V for Windows, online backups are supported for virtual machines running on Windows 2008 R2 or 2012 only if the virtual machines being backed up have SCSI controllers.

Note:

The following storage on Hyper-V guest virtual machines are not supported for backup through the Virtual Server Agent:

  • Physical hard disks that are directly attached to a virtual machine

  • Storage accessed from a virtual machine by using an Internet SCSI (iSCSI) initiator within the guest operating system.

Enabling Online Backups of Windows 2012 Virtual Machines on 2008 R2 Hyper-V Servers

If a backup operation is performed on a Windows Server 2012 virtual machine running on a 2008 R2 Hyper-V server, the virtual machine may go offline temporarily.

To enable the virtual machines to stay online during backups, create the ScopeSnapshots Windows registry key on the Windows 2012 virtual machine.

Open Registry Editor, navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore and add the ScopeSnapshots registry key with a Dword (32-bit) value 0.

For more information, refer to the Microsoft article on Unable to perform online backup because scope snapshots are enabled.