Failed to read data from the VSS snapshot because the operating system responded with the following error: 'Incorrect Function'.

Question

Failed to read data from the VSS snapshot because the operating system responded with the following error: 'Incorrect Function'.

Answer 1

Hi Simon,

Hope you're doing well.

The error message you're encountering, "Failed to read data from the VSS snapshot because the operating system responded with the following error: 'Incorrect Function'," indicates an issue related to Volume Shadow Copy Service (VSS) writers. Let's troubleshoot this:

1. The error is often caused by a problem with one of the SQL Server instances. Identify the problematic SQL Server instance by examining the first recorded SQLVDI error in the event log.
2. Ensure that the database isn't in SINGLE_USER access mode during backup. Check if the database name contains any leading/trailing spaces or unprintable characters.
3. If you're dealing with Hyper-V, disable the "Backup" integration service for the specific virtual machine causing the error. Re-enable the service after running a successful test backup.

Remember to restart the system after re-registering writers and check the writer status.

Best Regards,

Ian Xue

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