The VSS_FILE_SPEC_BACKUP_TYPE enumeration is
used by writers to indicate their support of certain backup
operations—such as incremental or differential backup—on the
basis of file sets (a specified file or files).
File sets stored in the Writer Metadata Document are tagged with a bit mask (or bitwise OR) of
VSS_FILE_SPEC_BACKUP_TYPE values indicating the
following:
- Whether the writer and the requester have to evaluate a given file set for participation in the specified
type of backup operations
- Whether backing up the specified file will require a shadow copy
Syntax
typedef enum _VSS_FILE_SPEC_BACKUP_TYPE {
VSS_FSBT_FULL_BACKUP_REQUIRED = 0x00000001,
VSS_FSBT_DIFFERENTIAL_BACKUP_REQUIRED = 0x00000002,
VSS_FSBT_INCREMENTAL_BACKUP_REQUIRED = 0x00000004,
VSS_FSBT_LOG_BACKUP_REQUIRED = 0x00000008,
VSS_FSBT_FULL_SNAPSHOT_REQUIRED = 0x00000100,
VSS_FSBT_DIFFERENTIAL_SNAPSHOT_REQUIRED = 0x00000200,
VSS_FSBT_INCREMENTAL_SNAPSHOT_REQUIRED = 0x00000400,
VSS_FSBT_LOG_SNAPSHOT_REQUIRED = 0x00000800,
VSS_FSBT_ALL_BACKUP_REQUIRED = 0x0000000F,
VSS_FSBT_ALL_SNAPSHOT_REQUIRED = 0x00000F00
} VSS_FILE_SPEC_BACKUP_TYPE, *PVSS_FILE_SPEC_BACKUP_TYPE;
Constants
- VSS_FSBT_FULL_BACKUP_REQUIRED
A file set tagged with this value must be involved in all types of backup operations.
A writer tags a file set with this value to indicate to the requester that it expects a copy of the current
version of the file set to be available following the restore of any backup operation with a
VSS_BACKUP_TYPE of
VSS_BT_FULL.
- VSS_FSBT_DIFFERENTIAL_BACKUP_REQUIRED
A writer tags a file set with this value to indicate to the requester that it expects a copy of the current
version of the file set to be available following the restore of any backup operation with a
VSS_BACKUP_TYPE of
VSS_BT_DIFFERENTIAL.
This value is not supported for express writers.
- VSS_FSBT_INCREMENTAL_BACKUP_REQUIRED
A writer tags a file set with this value to indicate to the requester that it expects a copy of the current
version of the file set to be available following the restore of any backup operation with a
VSS_BACKUP_TYPE of
VSS_BT_INCREMENTAL.
This value is not supported for express writers.
- VSS_FSBT_LOG_BACKUP_REQUIRED
A writer tags a file set with this value to indicate to the requester that it expects a copy of the current
version of the file set to be available following the restore of any backup operation with a
VSS_BACKUP_TYPE of
VSS_BT_LOG.
This value is not supported for express writers.
- VSS_FSBT_FULL_SNAPSHOT_REQUIRED
A file set tagged with this value must be backed up from a shadow copy of a volume (and never from the
original volume) when participating in a backup operation with a
VSS_BACKUP_TYPE of
VSS_BT_FULL.
- VSS_FSBT_DIFFERENTIAL_SNAPSHOT_REQUIRED
A file set tagged with this value must be backed up from a shadow copy of a volume (and never from the
original volume) when participating in a backup operation with a
VSS_BACKUP_TYPE of
VSS_BT_DIFFERENTIAL.
- VSS_FSBT_INCREMENTAL_SNAPSHOT_REQUIRED
A file set tagged with this value must be backed up from a shadow copy of a volume (and never from the
original volume) when participating in a backup operation with a
VSS_BACKUP_TYPE of
VSS_BT_INCREMENTAL.
- VSS_FSBT_LOG_SNAPSHOT_REQUIRED
A file set tagged with this value must be backed up from a shadow copy of a volume (and never from the
original volume) when participating in a backup operation with a
VSS_BACKUP_TYPE of
VSS_BT_LOG).
- VSS_FSBT_ALL_BACKUP_REQUIRED
The default file backup specification type. A file set tagged with this value must always participate in
backup and restore operations.
- VSS_FSBT_ALL_SNAPSHOT_REQUIRED
The shadow copy requirement for backup. A file set tagged with this value must always be backed up from a
shadow copy of a volume (and never from the original volume) when participating in a backup operation.
Remarks
When a writer sets a backup-required value of the
VSS_FILE_SPEC_BACKUP_TYPE enumeration, it is
indicating that the requester perform the backup in such a way that, when the backup is restored, the current
version of the file set is restored. Typically, this means that the file set is copied as part of the backup.
This setting can be overridden if a file is added to the Backup Components Document as a differenced file
(using
IVssComponent::AddDifferencedFilesByLastModifyTime)
or as a partial file (using
IVssComponent::AddPartialFile).
If a file is added as a differenced file, the writer establishes criteria by which the requester should decide
whether or not to actually copy a file to a backup medium. A writer typically adds differenced files to the Backup
Components Document for inclusion in a backup
PostSnapshot event (see
CVssWriter::OnPostSnapshot). See
Incremental and Differential Backups
for details.
When a writer sets a shadow copy-required value of the
VSS_FILE_SPEC_BACKUP_TYPE enumeration, it
indicates that the file set should be backed up from a shadow-copied volume. File sets not tagged with a
shadow copy-required value can be backed up from the original volume.
Writers set VSS_FILE_SPEC_BACKUP_TYPE values
while handling an Identify event (see
CVssWriter::OnIdentify).
A bit mask (or bitwise OR) of
VSS_FILE_SPEC_BACKUP_TYPE values can be applied
to a file set when adding it to a component using the
IVssCreateWriterMetadata::AddFilesToFileGroup,
IVssCreateWriterMetadata::AddDatabaseFiles, or
IVssCreateWriterMetadata::AddDatabaseLogFiles
method.
If no explicit file specification backup type is supplied during the addition of a file specification to a
component, the specification is tagged with the default
VSS_FILE_SPEC_BACKUP_TYPE value:
(VSS_FSBT_ALL_BACKUP_REQUIRED | VSS_FSBT_ALL_SNAPSHOT_REQUIRED).
Requesters or writers can recover a file set's file specification backup type by using the
IVssWMFiledesc::GetBackupTypeMask
method.
Requirements
| Minimum supported client | Windows Vista |
|---|
| Minimum supported server | Windows Server 2003 |
|---|
| Header | Vss.h |
|---|
See Also
- Incremental and Differential Backups
- IVssWMFiledesc::GetBackupTypeMask
- IVssCreateWriterMetadata::AddFilesToFileGroup
- IVssCreateWriterMetadata::AddDatabaseFiles
- IVssCreateWriterMetadata::AddDatabaseLogFiles
- IVssComponent::AddDifferencedFilesByLastModifyTime
- IVssComponent::AddPartialFile
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Build date: 10/29/2009