Editing Shadow Copy (section)

==History==
{{Update|section|date=August 2015}}

===Windows XP and Server 2003===
''Volume Snapshot Service'' was first added to Microsoft Windows in [[Windows XP]]. It can only create temporary snapshots, used for accessing stable on-disk version of files that are opened for editing (and therefore locked). This version of VSS is used by [[NTBackup]].

The creation of persistent snapshots (which remain available across reboots until specifically deleted) has been added in [[Windows Server 2003]], allowing up to 512 snapshots to exist simultaneously for the same volume. In Windows Server 2003, VSS is used to create incremental periodic snapshots of data of changed files over time. A maximum of 64 snapshots are stored on the server and are accessible to clients over the network. This feature is known as ''Shadow Copies for Shared Folders'' and is designed for a [[client–server model]].<ref>{{cite web|title=Shadow Copy Client Download|url=https://technet.microsoft.com/en-us/windowsserver/bb405951.aspx|website=[[Microsoft TechNet|TechNet]]|publisher=[[Microsoft]]|access-date=21 October 2014}}</ref> Its client component is included with Windows XP SP2 or later, and is available for installation on [[Windows 2000]] SP3 or later, as well as Windows XP RTM or SP1.<ref>{{cite web |url=http://blogs.msdn.com/adioltean/archive/2004/12/17/323742.aspx |title=Tips for deploying Shadow {{sic|copies|nolink=yes}} for Shared Folders |date=17 December 2004 |access-date=21 April 2009 |last=Oltean |first=Adi |work=Antimail |publisher=[[Microsoft]] }}</ref>

{{Infobox software
| name = vssadmin
| logo = 
| screenshot = 
| screenshot size = 
| caption = 
| developer = [[Microsoft]]
| released = 
| latest release version = 1.1
| latest release date = 
| operating system = [[Microsoft Windows]]
| genre = [[Command (computing)|Command]]
| license = [[Proprietary software|Proprietary]] [[commercial software]]
| website = {{URL|https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/vssadmin}}
}}
Windows XP<ref name="msdn article">{{cite web |title=Windows XP - Volume Shadow Copy Service |url= http://msdn.microsoft.com/en-us/library/windows/desktop/bb968832(v=vs.85).aspx |work=[[MSDN]] |publisher= [[Microsoft]] |access-date= 31 May 2013}}</ref> and later include a command line utility called <code>vssadmin</code> that can list, create or delete volume shadow copies and list installed shadow copy writers and providers.<ref>{{cite web |url = https://technet.microsoft.com/en-us/library/cc754968.aspx  |title = Vssadmin  |work = Windows Server 2008 and Windows Server 2008 R2 documentations. [[Microsoft TechNet|TechNet Library]] |at = Windows Server Commands, References, and Tools  |publisher = Microsoft |date = 28 September 2007 |access-date = 27 March 2012}}</ref>

===Windows Vista, 7 and Server 2008 ===
Microsoft updated a number of Windows components to make use of Shadow Copy. [[Backup and Restore]] in [[Windows Vista]], [[Windows Server 2008]], [[Windows 7]] and [[Windows Server 2008 R2]] use shadow copies of files in both file-based and sector-by-sector backup. The ''System Protection'' component uses VSS when creating and maintaining periodic copies of system and user data on the same local volume (similar to the Shadow Copies for Shared Folders feature in Windows Server); VSS allows such data to be locally accessed by [[System Restore]].

System Restore allows reverting to an entire previous set of shadow copies called a ''restore point''.<ref>
Compare:{{cite web
| url            = http://answers.microsoft.com/en-us/windows/forum/windows_vista-files/information-about-spp-folder-in-windows-vista/f050c2c8-2e8f-4092-9012-cd42c26ac18f?auth=1
| title          = Information about SPP folder in Windows vista 
| date           = 2010-08-20
| website        = Microsoft Community
| publisher      = Microsoft
| access-date    = 2015-07-22
| quote          = SPP stand for Shared Protection Point and is used by windows to store information on restore point.
}} 
</ref><ref>
Compare:
{{cite web
 |url= https://blogs.technet.microsoft.com/filecab/2009/09/16/diagnosing-failures-in-windows-server-backup-part-1-vssspp-errors/
 |title= Diagnosing Failures in Windows Server Backup – Part 1 (VSS/SPP Errors)
 |last= Barreto
 |first= Jose
 |date= 2009-09-16
 |website= Storage at Microsoft: The official blog of the Windows and Windows Server storage engineering teams
 |publisher= Microsoft Corporation
 |access-date= 2017-09-11
 |quote= [...] the origin of the error is in an underlying layer such as Volume Shadow Copy Service (VSS), Shared Protection Point (SPP), or other applications that plug into VSS framework.
}}
</ref>
Prior to Windows Vista, System Restore depended on a file-based filter that watched for changes to files with a certain set of extensions, and then copied files before they were overwritten.<ref>{{cite book |last1= Russinovich |first1= Mark E. |first2= David A. |last2= Solomon |title= Microsoft Windows Internals: Microsoft Windows Server 2003, Windows XP, and Windows 2000 |year= 2005 |publisher= [[Microsoft Press]] |location= [[Redmond, WA]] |isbn= 0-7356-1917-4 |edition= 4 |pages= [https://archive.org/details/isbn_9780735619173/page/706 706–711] |url-access= registration |url= https://archive.org/details/isbn_9780735619173/page/706 }}</ref><ref>{{cite web|title= Windows Backup|url= http://www.microsoft.com/middleeast/windowsvista/features/foreveryone/backup.mspx|work= Windows Vista portal|publisher= [[Microsoft]]|access-date= 11 January 2014|archive-url= https://web.archive.org/web/20070510204203/http://www.microsoft.com/middleeast/windowsvista/features/foreveryone/backup.mspx|archive-date= 10 May 2007}}</ref><ref name="BackupGuide">{{cite journal|last= Fok|first= Christine|title= A Guide to Windows Vista Backup Technologies|url= https://technet.microsoft.com/en-us/magazine/2007.09.backup.aspx|journal= TechNet Magazine|publisher= [[Microsoft]]|access-date= 11 January 2014|date= September 2007}}</ref> In addition, a part of [[Windows Explorer]] called ''Previous Versions'' allows restoring individual files or folders locally from restore points as they existed at the time of the snapshot, thus retrieving an earlier version of a file or recovering a file deleted by mistake.

{{Infobox software
| name                   = diskshadow
| logo                   = 
| screenshot             = 
| screenshot size        = 
| caption                = 
| developer              = [[Microsoft]]
| released               = 
| latest release version = 
| latest release date    = 
| operating system       = [[Microsoft Windows]]
| genre                  = [[Command (computing)|Command]]
| license                = [[Proprietary software|Proprietary]] [[commercial software]]
| website                = {{URL|https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/diskshadow}}
}}
Finally, Windows Server 2008 introduces the <code>diskshadow</code> utility which exposes VSS functionality through 20 different commands.<ref>{{Cite web
 |url = https://technet.microsoft.com/en-us/library/cc772172%28WS.10%29.aspx
 |title = Diskshadow
 |work = Windows Server 2008 and Windows Server 2008 R2 documentations. [[Microsoft TechNet|TechNet Library]]
 |at = Windows Server Commands, References, and Tools
 |publisher = Microsoft Corporation
 |date = 28 September 2007
 |access-date = 27 March 2012
}}</ref>

The system creates shadow copies automatically once per day, or when triggered by the backup utility or installer applications which create a restore point.<ref>{{cite web
 |url= https://technet.microsoft.com/en-us/library/cc749185.aspx 
 |title= Selected Scenarios for Maintaining Data Integrity with Windows Vista
 |work= TechNet
 |publisher= Microsoft Corporation
}}</ref><ref>{{cite web |url= https://technet.microsoft.com/en-us/magazine/2007.09.backup.aspx|title= A Guide to Windows Vista Backup Technologies|publisher= Microsoft}}</ref> The "Previous Versions" feature is available in the Business, Enterprise, and Ultimate [[Windows Vista editions | editions of Windows Vista]]<ref>{{cite web
 |url= http://www.microsoft.com/windows/products/windowsvista/footnotes.mspx 
 |title= Volume Shadow Copy and "Previous Versions" feature in Windows Vista
 |publisher= Microsoft Corporation
}}</ref> and in all [[Windows 7 editions]]. The Home Editions of Vista lack the "Previous Versions" feature, even though the ''Volume Snapshot Service'' is included and running. Using third-party tools it is still possible to restore previous versions of files on the local volume.<ref>
[http://www.shadowexplorer.com/ ShadowExplorer allows restoring lost or altered files]
</ref>
Some of these tools also allow users to schedule snapshots at user-defined intervals, configure the storage used by volume-shadow copies and compare files or directories from different points-in-time using snapshots.<ref>
[http://www.bearsontheloose.com/ TimeTraveler adds a timeline to Windows Explorer allowing the user to open, restore or compare files or directories from points-in-time]
</ref>
Windows 7 also adds native support through a GUI to configure the storage used by volume-shadow copies.

===Windows 8 and Server 2012===
While supporting persistent shadow copies, [[Windows 8]] lacks the GUI portion necessary to browse them; therefore the ability to browse, search or recover older versions of files via the ''Previous Versions'' tab of the ''Properties'' dialog of files was removed for local volumes. However, using third party tools (such as ShadowExplorer) it is possible to recover that functionality.  The feature is fully available in [[Windows Server 2012]].<ref>{{cite web|url=http://msdn.microsoft.com/en-us/library/windows/desktop/hh848072%28v=vs.85%29.aspx|title=Previous versions UI removed for local volumes (Windows)|access-date=17 November 2012}}</ref>

===Windows 10===
Windows 10 restored the Previous Versions tab that was removed in Windows 8; however, in earlier builds it depended upon the File History feature instead of Volume Shadow copy.  Current builds now allow restoration from both File History and System Protection (System Restore) points, which use Volume Shadow Copy.<ref>{{cite web |last1=Saluste |first1=Margus |title=File History in Windows 8, 8.1 and 10 |url=https://www.winhelp.us/file-history-in-windows-8.html |website=WinHelp.us |access-date=18 March 2018 |archive-url=https://web.archive.org/web/20201225185236/https://www.winhelp.us/file-history-in-windows-8.html |archive-date=25 December 2020 |url-status=dead}}</ref>

=== Windows 11 ===
Windows 11 retains the same Previous Versions and File History feature introduced in Windows 10, although it is disabled by default.<ref>{{Cite web |last=Huc |first=Mauro |date=2023-03-08 |title=How to enable Previous Versions to recover files on Windows 11 - Pureinfotech |url=https://pureinfotech.com/enable-previous-versions-windows-11/ |archive-url=https://web.archive.org/web/20230527181204/https://pureinfotech.com/enable-previous-versions-windows-11/ |archive-date=May 27, 2023 |access-date=2023-07-19 |website=Pureinfotech • Windows 10 & Windows 11 help for humans |language=en-US}}</ref>

===Samba Server===
[[Samba (software)|Samba]] on Linux is capable of providing Shadow Copy Service on an [[Logical Volume Manager (Linux)|LVM]]-backed storage or with an underlying [[ZFS]] or [[btrfs]].<ref>{{cite web |url=http://www.samba.org/samba/docs/man/Samba-HOWTO-Collection/VFS.html | title=Samba HOWTO Collection, Part III. Advanced Configuration | access-date=2 October 2012 }}</ref><ref>{{cite web|url=https://github.com/zfsonlinux/zfs-auto-snapshot/wiki/Samba|title=zfsonlinux/zfs-auto-snapshot|website=GitHub|access-date=18 March 2018}}</ref><ref>{{cite web|url=https://forum.openmediavault.org/index.php/Thread/7331-GUIDE-Windows-Previous-Versions-and-Samba-Btrfs-Atomic-COW-Volume-Shadow-Copy/|title=[GUIDE] Windows Previous Versions and Samba (Btrfs - Atomic COW - Volume Shadow Copy)|website=openmediavault}}</ref>