DsBackupRead function
[This function is available for use in the operating systems specified in the Requirements section. It may be altered or unavailable in subsequent versions. Beginning with Windows Vista, use Volume Shadow Copy Service (VSS) instead.]
The DsBackupRead function reads a block of data from the current open file, into a buffer. The client application is expected to call this function repeatedly until the entire backup file has been received. The DsBackupOpenFile function provides the entire size of the backup file.
Syntax
HRESULT DsBackupRead(
_In_ HBC hbc,
_In_ PVOID pvBuffer,
_In_ DWORD cbBuffer,
_Out_ PDWORD pcbRead
);
Parameters
-
hbc [in]
-
Contains the backup context handle obtained with the DsBackupPrepare function.
-
pvBuffer [in]
-
Pointer to a buffer that receives the data. This buffer must be at least cbBuffer bytes in size.
-
cbBuffer [in]
-
Contains the size, in bytes, of the buffer at pvBuffer. This value must be a multiple of 8192 and must be greater than or equal to 24576.
-
pcbRead [out]
-
Pointer to a DWORD value that receives the actual number of bytes read. This may be less than the number of bytes requested because some transports fragment the buffer being transmitted instead of filling the entire buffer with data.
Return value
Returns S_OK if the function is successful or a Win32 or RPC error code otherwise. Possible error codes include the following.
-
ERROR_INVALID_PARAMETER
-
One or more parameters are not valid.
-
ERROR_HANDLE_EOF
-
The end of the backup file was reached.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows Vista |
| Minimum supported server |
Windows Server 2008 |
| Header |
|
| Library |
|
| DLL |
|