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Hyper-V Protection Issues

Updated: February 1, 2010

Applies To: System Center Data Protection Manager 2007

The following table provides troubleshooting guidance on protection issues for computers running Hyper-V Servers.

Hyper-V Server Protection Issues


Issue Possible Cause Resolution

Backup fails on the virtual machine with unknown error 0x800423f3.

The Virtual Server VSS Writer service does not support online backup for the client virtual machine.

Use Windows Event Viewer on the Virtual Server machine to find if Event ID 1044 exists. If this event exists, the virtual machine cannot perform online backups.

You can perform offline backups by updating the following registry key:

Set HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Virtual Server\1.0\Backup\BackupType\<VMNAME> to 0.

Online backup fails.

Online backups fails if the virtual machine contains volumes that do not support shadow copies (FAT 32 file systems). Additionally, if the shadow copies exist on different virtual machine volumes, the backup fails.

Install Knowledge Base article 940349 “Availability of a Volume Shadow Copy Service (VSS) update rollup package for Windows Server 2003 to resolve some VSS snapshot issues” ( on the virtual machine.

Ensure that the virtual machine is running before configuring the backup, and then delete the entries for the virtual machines for which the online backup is failing. Set HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Virtual Server\1.0\Backup\BackupType.