MABS v2: Error [0x8007007b] when performing a System State Backup on a DC running on a VMware VM

8:33 am in Azure, Azure Backup, Azure Backup Server, Cloud, Error [0x8007007b], MABS, MABS v2, Power, PowerShell, VMware by Wim Matthyssen

While configuring a Microsoft Azure Backup Server (MABS) v2 at a customer site, I encountered a problem while performing a System State Backup of their domain controllers (DC’s). The Protection Status showed Replica is inconsistent.

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When looking in the Monitoring tab, following detailed message is show:

DPM cannot create a backup because Windows Server Backup (WSB) on the protected computer encountered an error (WSB Event ID: 517, WSB Error Code: 0x605A140).(ID 30229 Details: Internal error code: 0x8099ED0)

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Because the first part of making a System State Backup is done by the local Windows Server Backup (WSB) feature, logon to the protected server and open Windows Server Backup (Server Manager – Tools – Windows Server Backup). There a message was shown indicating that the last backup has Failed.

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To view the error message a bit more in detail, open the Windows Server backup log file (with the exact date and timestamp) located in C:\Windows\Logs\WindowsServerBackup.

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In the log file the following error message was shown:

Error in backup of C:\windows\\systemroot\ during enumerate: Error [0x8007007b] The filename, directory name, or volume label syntax is incorrect.

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When looking in the Event Viewer (Application log) I could also find the following errors (CAPI2 – 513, Backup – 517):

Event ID 513

Cryptographic Services failed while processing the OnIdentity() call in the System Writer Object.

Details:

AddLegacyDriverFiles: Unable to back up image of binary Microsoft Link-Layer Discovery Protocol.

System Error:

Access is denied.

Event ID 517

The backup operation that started at ‘‎2017‎-‎11‎-‎16T15:16:22.000076700Z’ has failed with following error code ‘0x80780049′ (None of the items included in backup were backed up.). Please review the event details for a solution, and then rerun the backup operation once the issue is resolved.

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Because all those errors descriptions do not really tell you what exactly is going wrong causing the backup to fail, you need to use the Diskshadow command-line tool to determine if there is an issue with the functionality of the VSS service or any of the application independent VSS writers.

To open the Diskshadow tool interface start PowerShell with elevated privileges and enter the below commands to write the output to a logfile.

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When the logfile (c:\out.txt) is created open it with notepad and search for \\.

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In my case, I found out there was an issue with the vsock.sys driver, which is part of the VMware vSockets Service and which is usually located in the C:\Windows\system32\drivers folder.

To fix the issue open the Registry Editor and go to the following location, HKLM\system\controlset001\services\vsock and changed the Start value to 1.

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Also change the ImagePath entry from \SystemRoot\system32\DRIVERS\vsock.sys to system32\DRIVERS\vsock.sys.

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When you have changed all those registry keys, logon to your MABS server and right click the failed System State backup and Perform a consistency check… (be aware that this could take a while). If the fix also solved your issue it would show OK when completed.

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Hope this helps whenever you face the same error in your MABS environment. If you have any questions feel free to contact me trough my Twitter handle.

Wim Matthyssen (@wmatthyssen)