Windows Server 2016 Datacenter backup job fails

Question

Our Windows server 2016 Datacenter with Hyper-V service uses Windows backup for backing up all the server state and data. In the last few months, Windows backup started generating errors. Backup process fails randomly, with no change in the system we would do on purpose, so we are trying to figure out what could be the cause. The errors, that we can get from the logs are these:

The backup operation started on 2021-05-02 T22: 35: 50.881021600Z failed with error code 0x80780166 (An error occurred in Windows Backup while writing data to the backup destination.). See the event details for a solution to the problem, and then run the backup operation again after it is resolved.

The backup operation started on 2021-05-02 T22: 35: 50.881021600Z failed with error code 0x80780166 (An error occurred in Windows Backup while writing data to the backup destination.). See the event details for a solution to the problem, and then run the backup operation again after resolving it.

The backup operation started on 2021-05-01 T22: 35: 20.792061300Z failed to back up volumes. See the event details for a solution to the problem, and then run the backup operation again after resolving it.

It does not matter, if we backup on iSCSI target, or even USB external device. The only thing, that helps is restarting the whole machine. It seems, that the problem is connected with the shadow copy service. And when we run the backup manually (not on schedule) the job is finished OK.

Would anybody have a suggestion, what can cause the problem ? Or any trick how can we run some deeper diagnostics ?

Thanks

Answer 1

Hi,

Thanks for posting on our forum!

Based on your descriptions, I suppose the issue is in accordance with VSS, as you guessed. Windows Backup can run into a allocation problem for Volume Shadow Copy Service (VSS). It may try to prevent the deletion of all your backups to benefit the newest one only. Firstly, check if you have set the status of the VSS service to Automatic.

1) Press Windows key + R to open up a Run dialog box. Once you’re inside the Run box, type “service.msc” and press Enter to open up the Services window.

2) Once you’re inside the Services screen, scroll down through the list of Services (Local) and locate Volume Shadow Copy. Once you see it, right-click on it and choose Properties from the newly appeared context menu.

3) Once you’re inside the Properties screen of the Volume Shadow Copy Service, select the General tab from the list of menu options and change the Startup type to Automatic. Next, click on Apply to save the changes.

4) Restart your computer and repeat the action that was triggering the 0x80780166 error code at the next startup.

Then, you can follow the articles below to set limit for shadow copy size (instead of using the default "No Limit"):

http://desk.plus/windows-backup-encountered-error-writing-data-backup-target/

(Please note: Information posted in the given link is hosted by a third party. Microsoft does not guarantee the accuracy and effectiveness of information.)

Finally, I found a blog which discusses a similar issue with yours and I think you may be interested in it:

https://social.technet.microsoft.com/Forums/Lync/en-US/d4c29a87-4f57-46d0-91a7-4bd4c2f20a0a/server-backup-is-failing-after-completing-50-with-this-error-windows-server-backup-encountered-an?forum=windowsbackup

Thanks for your support! Have a wonderful day! : )

Best regards
Joan

---

If the Answer is helpful, please click "Accept Answer" and upvote it.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.