...
BugZero found this defect 3216 days ago.
A Veeam Agent for Microsoft Windows backup job configured to operate in file-level backup mode with an entire volume selected and individual folders excluded, may fail with the error shown below. Unable to exclude files from snapshot: Shadow Copy Optimization Writer timed out.
The issue is caused by a timeout of the MS Copy Optimization Writer due to a large number of excluded files. In such cases, the Application Event Log on the affected machine may contain entries similar to the one below: Source: VSS Event ID: 8220 Level: Information Operation: OnPostSnapshot event PostSnapshot Event Context: Execution Context: Shadow Copy Optimization Writer Writer Name: Shadow Copy Optimization Writer
To workaround this VSS issue, two possible approaches are suggested: Option 1: Reduce the number of excluded folders until the warning no longer appears. Option 2: Instead of selecting an entire volume within file-level backup and excluding folders, select only the individual folders that need to be backed up.