IVssBackupComponents::GetWriterStatus method (vsbackup.h)

Article
10/13/2021

The GetWriterStatus method returns the status of the specified writer.

Syntax

HRESULT GetWriterStatus(
  [in]  UINT             iWriter,
  [out] VSS_ID           *pidInstance,
  [out] VSS_ID           *pidWriter,
  [out] BSTR             *pbstrWriter,
  [out] VSS_WRITER_STATE *pnStatus,
  [out] HRESULT          *phResultFailure
);

Parameters

[in] iWriter

Index of the writer whose metadata is to be retrieved. The value of this parameter is an integer from 0 to n–1 inclusive, where n is the total number of writers on the current system. The value of n is returned by IVssBackupComponents::GetWriterStatusCount.

[out] pidInstance

The address of a caller-allocated variable that receives the instance identifier of the writer.

[out] pidWriter

The address of a caller-allocated variable that receives the identifier for the writer class.

[out] pbstrWriter

The address of a caller-allocated variable that receives a string containing the name of the specified writer.

[out] pnStatus

The address of a caller-allocated variable that receives a VSS_WRITER_STATE enumeration value.

[out] phResultFailure

The address of a caller-allocated variable that receives the HRESULT failure code that was returned by the writer.

The following are the supported values for pHrResultFailure.

Value	Meaning
S_OK	The writer was successful.
VSS_E_WRITERERROR_INCONSISTENTSNAPSHOT	The shadow copy contains only a subset of the volumes needed by the writer to correctly back up the application component.
VSS_E_WRITERERROR_OUTOFRESOURCES	The writer ran out of memory or other system resources. The recommended way to handle this error code is to wait ten minutes and then repeat the operation, up to three times.
VSS_E_WRITERERROR_TIMEOUT	The writer operation failed because of a time-out between the Freeze and Thaw events. The recommended way to handle this error code is to wait ten minutes and then repeat the operation, up to three times.
VSS_E_WRITERERROR_RETRYABLE	The writer failed due to an error that would likely not occur if the entire backup, restore, or shadow copy creation process was restarted. The recommended way to handle this error code is to wait ten minutes and then repeat the operation, up to three times.
VSS_E_WRITERERROR_NONRETRYABLE	The writer operation failed because of an error that might recur if another shadow copy is created. For more information, see Event and Error Handling Under VSS.
VSS_E_WRITER_NOT_RESPONDING	The writer is not responding.
VSS_E_WRITER_STATUS_NOT_AVAILABLE	The writer status is not available for one or more writers. A writer may have reached the maximum number of available backup and restore sessions. Windows Vista, Windows Server 2003 and Windows XP: This value is not supported.

Return value

The following are the valid return codes for this method.

Value	Meaning
S_OK	Successfully returned the status of the specified writer. Note that the value of the pHrWriterFailure parameter must be checked to verify that the writer was successful. The writer failure codes can be among those listed in VsWriter.h and in Writer Errors and Vetoes.
E_INVALIDARG	One of the parameter values is not valid.
E_OUTOFMEMORY	The caller is out of memory or other system resources.
VSS_E_BAD_STATE	The backup components object is not initialized, this method has been called during a restore operation, or this method has not been called within the correct sequence.
VSS_E_OBJECT_NOT_FOUND	The specified writer does not exist.
VSS_E_UNEXPECTED	Unexpected error. The error code is logged in the error log file. For more information, see Event and Error Handling Under VSS. Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP: This value is not supported until Windows Server 2008 R2 and Windows 7. E_UNEXPECTED is used instead.

Remarks

A requester must call the asynchronous operation IVssBackupComponents::GatherWriterStatus and wait for it to complete prior to calling GetWriterStatus.

When the caller has finished accessing the status information returned by this method, it should call SysFreeString to free the memory held by the pbstrWriter parameter.

The VSS_E_WRITERERROR_XXX values returned in the pHrResultFailure parameter are generated by writers. VSS_E_WRITER_NOT_RESPONDING and VSS_E_WRITER_STATUS_NOT_AVAILABLE are generated by VSS.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	vsbackup.h (include VsBackup.h, Vss.h, VsWriter.h)
Library	VssApi.lib