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VssVolumeSnapshotAttributes Enumeration
Allows additional attributes to be specified for a shadow copy. The context of a shadow copy (as set by the SetContext method in IVssBackupComponents method) may be modified by a bitmask that contains a valid combination of VssVolumeSnapshotAttributes and VssSnapshotContext enumeration values.

Namespace: Alphaleonis.Win32.Vss
Assembly: AlphaVSS.Common (in AlphaVSS.Common.dll) Version: 1.3.0.0 (1.3.0.0)
Syntax
[FlagsAttribute]
public enum VssVolumeSnapshotAttributes
Members
  Member nameValueDescription
Persistent1The shadow copy is persistent across reboots. This attribute is automatically set for VssSnapshotContext contexts of AppRollbackClientAccessible, ClientAccessibleWriters and NasRollback. This attribute should not be used explicitly by requesters when setting the context of a shadow copy.
NoAutoRecovery2

Auto-recovery is disabled for the shadow copy.

A requester can modify a shadow copy context with a bitwise OR of this attribute. By doing this, the requester instructs VSS to make the shadow copy read-only immediately after it is created, without allowing writers or other applications to update components in the shadow copy.

Disabling auto-recovery can cause the shadow copy to be in an inconsistent state if any of its components are involved in transactional database operations, such as transactional read and write operations managed by Transactional NTFS (TxF). This is because disabling auto-recovery prevents incomplete transactions from being rolled back.

Disabling auto-recovery also prevents writers from excluding files from the shadow copy.

Windows Server 2003 and Windows XP: This value is not supported until Windows Vista.

ClientAccessible4

The specified shadow copy is a client-accessible copy, supports Shadow Copies for Shared Folders, and should not be exposed.

This attribute is automatically set for ClientAccessible and ClientAccessibleWriters.

This attribute should not be used explicitly by requesters when setting the context of a shadow copy.

NoAutoRelease8

The shadow copy is not automatically deleted when the shadow copy requester process ends. The shadow copy can be deleted only by a call to DeleteSnapshot(Guid, Boolean) or DeleteSnapshotSet(Guid, Boolean).

This attribute is automatically set for VssSnapshotContext contexts of Rollback, ClientAccessible, ClientAccessibleWriters and Rollback.

NoWriters16

No writers are involved in creating the shadow copy.

This attribute is automatically set for VssSnapshotContext contexts of NasRollback, FileShareBackup and ClientAccessible.

This attribute should not be used explicitly by requesters when setting the context of a shadow copy.

Transportable32

The shadow copy is to be transported and therefore should not be surfaced locally.

This attribute can be used explicitly by requesters when setting the context of a shadow copy, if the provider for shadow copy supports transportable shadow copies.

Windows Server 2003, Standard Edition, Windows Server 2003, Web Edition, and Windows XP: This attribute is not supported. All editions of Windows Server 2003 SP1 support this attribute.

NotSurfaced64

The shadow copy is not currently exposed.

Unless the shadow copy is explicitly exposed or mounted, this attribute is set for all shadow copies.

This attribute should not be used explicitly by requesters when setting the context of a shadow copy.

NotTransacted128

The shadow copy is not transacted.

A requester can modify a shadow copy context with a bitwise OR of this attribute. By doing this, the requester instructs VSS to disable built-in integration between VSS and transaction and resource managers.

Setting this attribute guarantees that the requester will not receive VssTransactionFreezeTimeoutException errors. However, it may cause unwanted consequences, such as the loss of transactional integrity or even data loss.

Windows Server 2003 and Windows XP: This value is not supported until Windows Vista.

HardwareAssisted65536

Indicates that a given provider is a hardware-based provider.

This attribute is automatically set for hardware-based providers.

This enumeration value cannot be used to manually set the context (using the SetContext(VssVolumeSnapshotAttributes) method) of a shadow copy by a bit mask (or bitwise OR) of this enumeration value and a valid shadow copy context value from VssSnapshotContext.

Differential131072

Indicates that a given provider uses differential data or a copy-on-write mechanism to implement shadow copies.

A requester can modify a shadow copy context with a bitwise OR of this attribute. By doing this, the requester instructs providers to create a shadow copy using a differential implementation. If no shadow copy provider installed on the system supports the requested attributes, a VssVolumeNotSupportedException error will be returned to AddToSnapshotSet(String, Guid).

Plex262144

Indicates that a given provider uses a PLEX or mirrored split mechanism to implement shadow copies.

A requester can modify a shadow copy context with a bitwise OR of this attribute. By doing this, the requester instructs the providers to create a shadow copy using a PLEX implementation. If no shadow copy provider installed on the system supports the requested attributes, a VssVolumeNotSupportedException error will be returned to AddToSnapshotSet(String, Guid).

Imported524288

The shadow copy of the volume was imported onto this machine using the ImportSnapshots method rather than created using the DoSnapshotSet method.

This attribute is automatically set if a shadow copy is imported.

This attribute should not be used explicitly by requesters when setting the context of a shadow copy.

ExposedLocally1048576

The shadow copy is locally exposed. If this bit flag and the ExposedRemotely bit flag are not set, the shadow copy is hidden.

The attribute is automatically added to a shadow copy context upon calling the ExposeSnapshot(Guid, String, VssVolumeSnapshotAttributes, String) method to expose a shadow copy locally.

This attribute should not be used explicitly by requesters when setting the context of a shadow copy.

ExposedRemotely2097152

The shadow copy is remotely exposed. If this bit flag and the ExposedLocally bit flag are not set, the shadow copy is hidden.

The attribute is automatically added to a shadow copy context upon calling the ExposeSnapshot(Guid, String, VssVolumeSnapshotAttributes, String) method to expose a shadow copy locally.

This attribute should not be used explicitly by requesters when setting the context of a shadow copy.

AutoRecover4194304

Indicates that the writer will need to auto-recover the component in CVssWriter::OnPostSnapshot.

This attribute should not be used explicitly by requesters when setting the context of a shadow copy.

RollbackRecovery8388608

Indicates that the writer will need to auto-recover the component in CVssWriter::OnPostSnapshot if the shadow copy is being used for rollback (for data mining, for example).

A requester would set this flag in the shadow copy context to indicate that the shadow copy is being created for a non-backup purpose such as data mining.

DelayedPostSnapshot16777216

Reserved for system use.

Windows Vista, Windows Server 2003, and Windows XP: This value is not supported until Windows Server 2008.

TxFRecovery33554432

Indicates that TxF recovery should be enforced during shadow copy creation.

Windows Vista, Windows Server 2003, and Windows XP: This value is not supported until Windows Server 2008.

Remarks
In the VSS API, these values are represented by the enumeration
See Also