"The VSS Diff failed" error
Issue
The "VSS Diff failed (An error occurred during the fast difference check; a slower method will be used instead)" issue has occurred.
Cause
This issue is usually caused by the shadow storage size being too small.
Resolution
Windows workstations 7, 8, 10, 11:
Use the command line and run the following command to resize the shadow storage:
vssadmin resize shadowstorage /for=X: /on=X: /maxsize=320MBXrepresents the disk letter (it is recommended to perform this operation on all accessible disks).
vssadmin resize shadowstorage /for=X: /on=X: /maxsize=30%After making the changes, run the backup task again. If it still fails, contact our technical support by submitting a request.
Windows Server:
Delete all shadow copies using the following two additional command line commands:
diskshadowdelete shadows allRun the backup again. If it still fails, contact our technical support by submitting a request.
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