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ISSUE: [VSSDatabaseExpt] VSS_E_UNEXPECTED_PROVIDER_ERROR (MS Exchange database backup)

Article ID: 8071
Reviewed: 07/07/2021

Product Version: CloudBacko Go 8.5 or above
Operating System: Windows

Problem Description

When performing either a scheduled or manual MS Exchange database backup job. The following backup errors are received in the backup report:

No. Type Timestamp Log
* info Using Temporary Directory …
* erro YYYY/MM/DD hh:mm:ss Cannot start shadow copy, reason =VSS_E_UNEXPECTED_PROVIDER_ERROR

The backup error persists even after the following actions have been performed.

  1. The MS Exchange version is updated to the latest service pack / rollup.
  2. The MS Exchange Server has been rebooted.
  3. The VSS writers have been re-registered using the CloudBacko Go_Install_home%\bin\RegisterVSS.bat

Checking the status of the VSS writers using the vssadmin list writers command shows the “Microsoft Exchange Writer” is still in a “Failed” state.



This issue can occur if there is not enough space on the Exchange server to create a VSS snapshot of the database. In other words, the maximum size of the shadow storage area is too small.


To resolve this issue, consider to resize the maximum shadow storage area on the MS Exchange server.

Refer to the following Microsoft Document for details on how to resize the shadow storage area:


UNEXPECTED, PROVIDER_ERROR, VSSDatabaseExpt, shadow storage, resize, VSS Writer, Microsoft Exchange Writer

public/issue/exchange_database_backup_vssdatabaseexpt_unexpected_provider_error_8071.txt · Last modified: 2021/07/07 17:04 by support