IVssExamineWriterMetadata::GetRestoreMethod method (vsbackup.h)

Article
10/13/2021

The GetRestoreMethod method returns information about how a writer wants its data to be restored.

Syntax

HRESULT GetRestoreMethod(
  [out] VSS_RESTOREMETHOD_ENUM *pMethod,
  [out] BSTR                   *pbstrService,
  [out] BSTR                   *pbstrUserProcedure,
  [out] VSS_WRITERRESTORE_ENUM *pwriterRestore,
  [out] bool                   *pbRebootRequired,
  [out] UINT                   *pcMappings
);

Parameters

[out] pMethod

Pointer to a VSS_RESTOREMETHOD_ENUM value that specifies file overwriting, the use of alternate locations specifying the method that will be used in the restore operation.

[out] pbstrService

If the value of pMethod is VSS_RME_STOP_RESTORE_START or VSS_RME_RESTORE_STOP_START, a pointer to a string containing the name of the service that is started and stopped. Otherwise, the value is NULL.

[out] pbstrUserProcedure

Pointer to the URL of an HTML or XML document describing to the user how the restore is to be performed. The value may be NULL.

[out] pwriterRestore

Pointer to a VSS_WRITERRESTORE_ENUM value specifying whether the writer will be involved in restoring its data.

[out] pbRebootRequired

Pointer to a Boolean value indicating whether a reboot will be required after the restore operation is complete. The value receives true if a reboot will be required, or false otherwise.

[out] pcMappings

Pointer to the number of alternate mappings associated with the writer.

Return value

The following are the valid return codes for this method.

Value	Meaning
S_OK	Successfully returned the restore method information.
S_FALSE	A restore method does not exist.
E_INVALIDARG	One of the parameter values is not valid.
E_OUTOFMEMORY	The caller is out of memory or other system resources.
VSS_E_INVALID_XML_DOCUMENT	The XML document is not valid. Check the event log for details. For more information, see Event and Error Handling Under VSS.
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

The caller must free the memory used by the pbstrUserProcedure and pbstrService parameters by calling SysFreeString.

A file should always be restored to its alternate location mapping if either of the following is true:

The restore method (set at backup time) is VSS_RME_RESTORE_TO_ALTERNATE_LOCATION.
Its restore target was set (at restore time) to VSS_RT_ALTERNATE.

In either case, if no valid alternate location mapping is defined, this constitutes a writer error.

A file can be restored to an alternate location mapping if :

The restore method is VSS_RME_RESTORE_IF_NOT_THERE and a version of the file is already present on disk.
The restore method is VSS_RME_RESTORE_IF_CAN_REPLACE and a version of the file is present on disk and cannot be replaced.

Again, if no valid alternate location mapping is defined, this constitutes a writer error.

An alternate location mapping is used only during a restore operation and should not be confused with an alternate path, which is used only during a backup operation.

For more information about restore methods, see Setting VSS Restore Methods.

If the restore method is VSS_RME_STOP_RESTORE_START or VSS_RME_RESTORE_STOP_START, a requester uses the name returned by pbstrService to determine which service must be stopped during and then restarted after restore. See Stopping Services For Restore by Requesters for information on writer participation in stopping and restarting services during a restore operation.

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