Event ID 8194 — Volume Shadow Copy Service Operations

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Applies To: Windows Server 2008

The Volume Shadow Copy Service (VSS) provides the ability to create a point in time image (shadow copy) of one or more volumes that can be used to perform backups. The service is also used during restores of applications.

Event Details

Product: Windows Operating System
ID: 8194
Source: VSS
Version: 6.0
Symbolic Name: VSS_ERROR_QI_IVSSWRITERCALLBACK
Message: Volume Shadow Copy Service error: Unexpected error querying for the IVssWriterCallback interface. hr = %1. This is often caused by incorrect security settings in either the writer or requestor process. %2

Resolve

Use VssAdmin to determine the cause of the error condition and then contact the appropriate vendor

Note: If this event occurs when you are installing or uninstalling Microsoft Office 2007 on Windows Vista, you can safely ignore it.

To troubleshoot this error condition, you first need to determine what caused it by using the VssAdmin command line tool. After determining the cause of the error condition, follow the steps indicated for each possible cause.

To perform these procedures, you must have membership in Administrators, or you must have been delegated the appropriate authority.

To use VssAdmin to determine the cause of the error condition:

  1. Open an elevated Command Prompt. Click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
  2. Type vssadmin list writers, and then press Enter.

The output of this command will tell you that the cause of the error condition is one of the following:

  • If the command does not respond, the Volume Shadow Copy Service (VSS) writer has encountered an internal problem which caused it to stop responding to incoming requests. To fix this problem, you should restart the service or process that hosts the writer. If this does not resolve the issue, restart the computer.
  • If the command reports the state of the writer as Retryable error, then the writer has encountered a temporary error that can be resolved by retrying the backup. To fix this error, run the backup again. If this does not resolve the issue after one or two attempts, restart the computer.
  • If the command reports the state of the writer as Non-retryable error, then the writer has encountered a permanent error that can be resolved by restarting the service or process that hosts the writer. If this does not resolve the issue, restart the computer. If restarting the computer does not resolve the issue, open Event Viewer as described in the "Open Event Viewer and view events related to VSS" section and look for events related to the service or process that hosts the writer, and provide this information to the vendor that is responsible for the writer.
  • If the command fails, event ID 8194 with source VSS will be logged in the Application log. Use Event Viewer to determine if this event has been logged. For more information, see the "Open Event Viewer and view events related to VSS" section. If this event has been logged, save the Event Log information related to event ID 8194, and provide this information to the vendor that is responsible for the writer.
  • If the command reports that all writers are operating without errors, this means that the error condition is not writer-related. In this case, you should contact the backup software vendor that created the VSS requester application.

To open Event Viewer and view events related to VSS:

  1. If Server Manager is not already open, click Start, click Administrative Tools, and then click Server Manager.
  2. In the console tree, expand Diagnostics, expand Event Viewer, expand Windows Logs, and then click Application.
  3. To filter the events so that only events with a Source of VSS are shown, in the Actions pane, click Filter Current Log. On the Filter tab, in the Event sources drop-down list, select the checkbox for VSS. Select other options as appropriate, and then click OK.
  4. To sort the displayed events by date and time, in the center pane, click the Date and Time heading.

Verify

To perform this procedure, you must have membership in Administrators, or you must have been delegated the appropriate authority.

To verify that the Volume Shadow Copy Service is started:

  1. Click Start, point to Administrative Tools, and then click Services.
  2. In the results pane, double-click Volume Shadow Copy.
  3. In Service status, make sure that the status is Started. If the status is not Started, click Start.
  4. Make sure Startup type is set to Manual.
  5. Click OK.

Volume Shadow Copy Service Operations

File Services