VSS_SUBSCRIBE_MASK enumeration (vswriter.h)

The VSS_SUBSCRIBE_MASK enumeration is used by a writer when subscribing to the VSS service. It indicates the events that the writer is willing to receive.

Syntax

typedef enum VSS_SUBSCRIBE_MASK {
  VSS_SM_POST_SNAPSHOT_FLAG = 0x00000001,
  VSS_SM_BACKUP_EVENTS_FLAG = 0x00000002,
  VSS_SM_RESTORE_EVENTS_FLAG = 0x00000004,
  VSS_SM_IO_THROTTLING_FLAG = 0x00000008,
  VSS_SM_ALL_FLAGS = 0xffffffff
} ;

Constants

VSS_SM_POST_SNAPSHOT_FLAG Value: 0x00000001 This enumeration value is reserved for future use. Specifies that the writer expects to be notified after the shadow copy it is participating in has completed. It will then call CVssWriter::OnPostSnapshot.
VSS_SM_BACKUP_EVENTS_FLAG Value: 0x00000002 Currently, VSS_SM_BACKUP_EVENTS_FLAG can be used as an argument only when combined through a bitwise OR with VSS_SM_RESTORE_EVENTS_FLAG. Specifies that the writer can expect to receive the following events: A PrepareForSnapshot event when the writer will call CVssWriter::OnPrepareSnapshot. A PrepareForBackup event when the writer will call CVssWriter::OnPrepareBackup. A Freeze event when the writer will call CVssWriter::OnFreeze. A BackupComplete event when the writer will call CVssWriter::OnBackupComplete. A Thaw event when the writer will call CVssWriter::OnThaw. A PostSnapshot event when the writer will call CVssWriter::OnPostSnapshot.
VSS_SM_RESTORE_EVENTS_FLAG Value: 0x00000004 Currently, VSS_SM_RESTORE_EVENTS_FLAG can be used as an argument only when combined through a bitwise OR with VSS_SM_BACKUP_EVENTS_FLAG. Specifies that the writer can expect to receive the following events: A PreRestore event when the writer will call CVssWriter::OnPreRestore. A PostRestore event when the writer will call CVssWriter::OnPostRestore.
VSS_SM_IO_THROTTLING_FLAG Value: 0x00000008 This enumeration value is reserved for future use.
VSS_SM_ALL_FLAGS Value: 0xffffffff This enumeration value is reserved for future use. Specifies that the writer expects to be notified for all events.

Remarks

A bit mask (or bitwise OR) of VSS_SUBSCRIBE_MASK values is used as an argument only to CVssWriter::Subscribe.

Currently, the only supported VSS_SUBSCRIBE_MASK bit mask is ( VSS_SM_BACKUP_EVENTS_FLAG | VSS_SM_RESTORE_EVENTS_FLAG).

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Header	vswriter.h

See also

CVssWriter::OnBackOffIOOnVolume

CVssWriter::OnBackupComplete

CVssWriter::OnContinueIOOnVolume

CVssWriter::OnPostRestore

CVssWriter::OnPostSnapshot

CVssWriter::OnPreRestore

CVssWriter::OnPrepareBackup

CVssWriter::Subscribe