How to Manage Shadow Copies

You can manage the Volume Shadow Copy service using the Vssadmin command-line tool from an elevated command prompt. You can use this tool to run the following commands:

• Vssadmin List Providers Lists registered Volume Shadow Copy providers. Windows 7 includes Microsoft Software Shadow Copy Provider 1.0.
• Vssadmin List Shadows Lists existing volume shadow copies, the time the shadow copy was created, and its location. The following sample output shows two shadow copies.

  vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
  (C) Copyright 2001-2005 Microsoft Corp.
  
  Contents of shadow copy set ID: {79f6e5e8-0211-43bf-9480-c65e51b4b40d}
  
    Contained 1 shadow copies at creation time: 12/20/2006 1:05:08 PM
       Shadow Copy ID: {26fc6f1c-9610-4c0c-b10b-7e9f6fab042c}
  	Original Volume: (C:)\\?\Volume{3e59796e-cf1b-11da-af4b-806d6172696f}\
  	Shadow Copy Volume: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1
  	Originating Machine: WIN7
  	Service Machine: WIN7
  	Provider: 'Microsoft Software Shadow Copy provider 1.0'
  	Type: DataVolumeRollback
  	Attributes: Persistent, No auto release, No writers, Differential
  
  Contents of shadow copy set ID: {d14c728d-ff85-4be1-b048-24f3aced48a9}
    Contained 1 shadow copies at creation time: 12/20/2006 4:42:12 PM
       Shadow Copy ID: {271752a4-e886-4c92-9671-10624ca36cd4}
  	Original Volume: (C:)\\?\Volume{3e59796e-cf1b-11da-af4b-806d6172696f}\
  	Shadow Copy Volume: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy2
  	Originating Machine: WIN7
  	Service Machine: WIN7
  	Provider: 'Microsoft Software Shadow Copy provider 1.0'
  	Type: DataVolumeRollback
  	Attributes: Persistent, No auto release, No Writers, Differential
  

• Vssadmin List ShadowStorage Lists the volume shadow storage space currently in use, the space that is reserved for future use (labeled as allocated), and the maximum space that might be dedicated. This space is used to store changes while a shadow copy is active. The following sample output was generated using a computer that currently has about 3 GB of files stored in a shadow copy, but that might allocate as much as 6.4 GB.

  Vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
  (C) Copyright 2001-2005 Microsoft Corp.
  
  Shadow Copy Storage association
     For volume: (C:)\\?\Volume{3e59796e-cf1b-11da-af4b-806d6172696f}\
     Shadow Copy Storage volume: (C:)\\?\Volume{3e59796e-cf1b-11da-af4b-
  806d6172696f}\
     Used Shadow Copy Storage space: 32.703 MB (0%)
     Allocated Shadow Copy Storage space: 1.904 GB (1%)
     Maximum Shadow Copy Storage space: 38.061 GB (30%)
  

• Vssadmin List Volumes Lists volumes that are eligible for shadow copies.
• Vssadmin List Writers Lists shadow copy writers, which support communicating with the Volume Shadow Copy service to ensure that files are captured in a consistent state. By default, subscribed writers include an operating system writer, a registry writer, a Windows Management Instrumentation (WMI) writer, and a search service writer, among others. SQL Server also provides a Volume Shadow Copy writer.
• Vssadmin Resize ShadowStorage Resizes Volume Shadow Copy storage. You can use this command to increase the maximum space that might be used by Volume Shadow Copy. Typically, this is unnecessary. However, if you discover that backups are failing on a computer because of an extremely high volume of changes during a backup and if Vssadmin List ShadowStorage reveals that the used Shadow Copy Storage space is at the maximum, you might be able to resolve the problem by manually increasing the maximum size.

Note Vssadmin in Windows 7 does not provide all of the commands that Windows Server 2008 provides because the ability to manually create and manage shadow copies typically is unnecessary on client computers.