SEP sesam Volume Shadow Copy Service (VSS) for Windows
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With the Volume Shadow Copy Service (VSS) opened files can be consistently backed up under Windows. For this a non-persistent snapshot (shadow) is taken of the volumes and then backed up (in Windows).
The data is stored in the saveset with original location, e.g. "C:\".
The total amount of VSS snaphosts is restricted to oper systems:
- under XP only one set (with some volumes) is allowed,
- other oper systems allow up to 64 sets.
This feature is for file backup only and won't work with the source system_state. All other backup types aren't supported yet.
ATTENTION: If the restricted total amount of created volumes will be exceeded then a VSS backup fails. The total amount includes VSS snapshots which may be created otherwise!
As VSS uses the Copy-on-Write method only the amount of space for data which is changed during backup is needed as additional space during backup. The non-persistent snapshot disappears after the backup and does not occupy a volume identifier. Differential and incremental backups are processed on the shadow. The restore is unaffected by changes of the backup method.
Having the Microsoft Auto-Updater running while an VSS Backup is done might result in backups failing (WIN32 API error: 21 - The Device is not ready). Please assure that the Auto-Updater is deactivated during the time the backup task is running.
- "How Volume Shadow Copy Service Works" http://technet.microsoft.com/en-us/library/cc785914.aspx
- "Shadow Copy" http://en.wikipedia.org/wiki/Shadow_Copy
A description using SEPsesam Pre-/Post-Interface for SEPsesam Version 3.0 is located under SEP sesam Volume Shadow Copy Service (VSS) for Windows via Pre/Post.
No installation is neccessary. All the needed components are included in the SEP Sesam kit.
With Sesam client version 4.0 or higher every path backup task of a Windows client will activate the VSS option automatically. You can deactivate it in the GUI task definition. In older Sesam client versions you have to set up the value -o vss in the options 1 tab in the backup options. The source is unaffected by this change and can be entered as usual or by browser.
- Client operating system: Windows XP, 2003, 2008
- Sesam Server from version 18.104.22.168
- Sesam Client from version 22.214.171.124
The SEP sesam kit contains all necessary components. Therefore there is no need to install further packages.
Activation of the VSS Shadow Backup
Establish a new backup task or modify an existing one for the client. Add option -o vss in field Save options in the task properties under tab Options 1. The task source is unchanged.