Windows Server Backup Volumes Greater Than 16TB Fails

Hi,

It seems a known limitation of the Windows Server Backup since Windows Server 2012. It is recommended to send feedback to Microsoft with Feedback Hub.

https://support.microsoft.com/en-us/windows/send-feedback-to-microsoft-with-the-feedback-hub-app-f59187f8-8739-22d6-ba93-f66612949332

Best Regards,

Ian Xue

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AFAIK there is no limit on Server Backup since 2012. You didn't specify what version of Server you're using. However your 16TB limit brings to mind NTFS's limit. NTFS doesn't support drives larger than 16TB at the default cluster size of 4KB. To have drives larger than that you have to use larger cluster sizes as discussed here. Also ReFS isn't supported, at least as of Server 2019 I believe.

I've experienced the following error message when backing up a 20TB volume on WS2022.
"Windows Server Backup- Volumes larger than 16777216 megabytes cannot be protected."

The server's WSB source and target were 8k in cluster size, yet we still receive the error.

To further test, in a Windows Server 2019 Standard lab VM I created a 20TB disk with 16k cluster size and a target of 40TB with 16k in size. The result was the same when clicking the backup button the aforementioned error is the result.

The following link was the only online reference that called out this limitation on Windows Server versions 2012 and later.

[http://kb.backupassist.com/print.php?aid=3425]