Use Diskshadow tool to check the functionality of the VSS service

Applicable to:

• Windows 8
• Windows 2008
• Windows 2012

Introduction

Diskshadow is a command-line tool that exposes the functionality provided by the Volume Shadow Copy Service (VSS). Diskshadow is included in Windows 8, Windows Server 2008 and Windows Server 2012 as an in-box VSS requester for hardware shadow copy scenarios.

Using Diskshadow you can check the functionality of the VSS service components and the application VSS writers independently from Acronis Software.

Solution

Troubleshoot VSS-related issues with the free Acronis VSS Doctor tool. If it didn't help and you still want to use Diskshadow, follow instructions below to check the VSS service and VSS writers.

Start the command prompt with elevated priviledges:

Start -> CMD -> Right click -> Run as Administrator

Enter the Diskshadow tool interface:

C:\Users\administrator> DISKSHADOW

Specify that the shadow copies will persist across program exit, reset, or restart:

DISKSHADOW> set context persistent

Set the verbose output on:

DISKSHADOW> set verbose on

Start a full backup session:

DISKSHADOW> begin backup

Specify the volumes to be included in the backup:

DISKSHADOW> add volume C: alias VolumeC

DISKSHADOW> add volume D: alias VolumeD

 

You can also specify the VSS Provider that will operate the shadow copy on the particular volume:

DISKSHADOW> add volume C: alias VolumeC provider {b5946137-7b9f-4925-af80-51abd60b20d5}

To view the current list of registered providers, type:

DISKSHADOW> list providers

Specify the writers that should be verified during the shadow copy creation:

DISKSHADOW> writer verify {a65faa63-5ea8-4ebc-9dbd-a0c4db26912a}

To view the list of writers on the system, type

DISKSHADOW> list writers

To verify that backup includes the Hyper-V Virtual Machines, verify the "Microsoft Hyper-V VSS Writer":

DISKSHADOW> writer verify {66841cd4-6ded-4f4b-8f17-fd23f8ddc3de}

After you have specified all volumes, providers and writers for backup, initiate the backup creation:

DISKSHADOW> create

During backup creation you will see following messages appearing in the command prompt, meaning that a particular component has been included into backup procedure and will be verified:

* Writer "WMI Writer" is included:
+ Component is included: \WMI

If one of the writers fails, you will see an error message similar to the following:

ERROR: The selected writer "SqlServerWriter" is in a faulty state.
- Status: 8 (VSS_WS_FAILED_AT_PREPARE_SNAPSHOT)
- Writer Failure code: 0x (VSS_E_WRITERERROR_NONRETRYABLE)
- Writer ID: {a65faa63-5ea8-4ebc-9dbd-a0c4db26912a}
- Instance ID: {8c57ad9a-8055-49e0-96ec-d8b41ea327eb}

Error on recent operation.
- HRESULT (returned): 80042301
- Error text: VSS_E_BAD_STATE

If any writer fails with an error, you have to troubleshoot this writer and make sure that before you continue using the VSS backup in Acronis Software, all VSS components function correctly.

Terminate the backup:

DISKSHADOW> end backup

Exit the Dishshadow tool:

DISKSHADOW> exit

(!)Sometimes you might be asked to collect metadata of VSS writers for investigation.

Example metadata collection for VSS writers:

1. set metadata c:\metadata.cab
2. set verbose on
3. begin backup
4. add volume c:
5. add volume d:
6. create
7. end backup

The result will be C:\metadata.cab. It will contain metadata of VSS writers, collected while backing up.

More information

After fixing issues with VSS components, re-attempt the backup with Diskshadow and make sure no errors appear.

See also:

• VSS Troubleshooting Guide
• VSS Log Files