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Unable to exclude files from snapshot: Shadow Copy Optimization Writer timed out


During a backup job Veeam Endpoint Backup returns the following warning:

Unable to exclude files from snapshot: Shadow Copy Optimization Writer timed out

The warning occurs in the following scenario: file-level backup is selected as backup mode, then a whole volume is selected, and a number of folders is explicitly excluded from backup.


The issue is caused by MS Copy Optimization Writer timeout due to a large number of excluded files. In such cases the Application Event Log on the affected workstation may contain entries similar to the one below:
Source:        VSS
Event ID:      8220
Level:         Information

   OnPostSnapshot event
   PostSnapshot Event

   Execution Context: Shadow Copy Optimization Writer
   Writer Name: Shadow Copy Optimization Writer


Two possible approaches are suggested.

1. Reduce the number of excluded folders until the warning is no longer displayed.
2. Rather than selecting a whole volume within file-level backup, it is recommended to select only the specific folders, that need to be processed.

More information

If you have further questions, open a support case as follows:

  1. Right-click the Veeam Endpoint Backup / Veeam Agent for Windows icon in the system tray and select Control Panel.
  2. Click the Support link at the top of the window.
  3. Click Technical Support to submit a support case to the Veeam Support Team directly from the product.
Veeam Agent for Microsoft Windows
1.1.2, 2.x
Last Modified:
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