Volume Shadow Copy Service

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Volume Shadow Copy Service ( VSS ), called volume shadow copy in localized Windows versions and colloquially referred to as “shadow copy ” for short, is a system service introduced with Windows XP for the generation and provision of version statuses.

more details

The volume shadow copy service was introduced with the Windows XP operating system and then made available in an expanded form with Windows Server 2003 , Windows Vista , Windows 7 , Windows Server 2008 , Windows Server 2012 , Windows Server 2016 and also Windows 10 . It is used for the simple creation and provision of versions (so-called snapshots ). This service saves modifications to files and folders within the framework of the previously provided hard disk capacity as part of up to 64 shadow copies, i.e. older versions.

The shadow copies themselves are write-protected. The primary advantage of this technology is that users can restore older versions of a file that have been overwritten without having to rely on the intervention of an administrator.

In addition, the Volume Shadow Copy Service can be used to create data backups of consistent states of the file systems or metadata that could otherwise be blocked by write operations (e.g. the registry or the system databases).

For this, programs can implement so-called “VSS writers” in order to store copies of their own currently open files in a consistent state in the shadow copy. The SQL server , for example, provides such a component. Some copy programs use this functionality to systems in the current clone operation.

In Windows XP a highly restricted version of VSS is included. Long-term storage of older versions is not possible. Only one temporary shadow copy can be made of each logical drive. This is z. B. used by backup solutions such as Acronis, Paragon, SEP sesam, NTBackup, Langmeier Backup, ShadowProtect, Bacula , Duplicati and Syncback Pro in order to be able to consistently save all files during operation. A shadow vshadow.execopy can also be created for Windows versions prior to Server 2008 using the command line program from the VSS SDK . With more recent versions, it is vssadmin.exealready available on the system.

It should be noted that Microsoft also uses the abbreviation VSS for Visual SourceSafe .

Web links

Individual evidence

  1. ↑ Volume Shadow Copy (Overview) - Page at Microsoft Technet ; As of January 4, 2011
  2. ↑ a b Windows Services: Volume Shadow Copy - Page at WinFAQ ; As of January 4, 2011
  3. ↑ c't - content 9/2009 - page 180 , website at heise online ; Status: July 3, 2010.