Wondering how to resolve the SQL Server backup error 18204? Worry not, our experts have put together some troubleshooting tips to help you out. Our SQL Server Support Service team is here to offer a hand with your queries and issues.

How to resolve SQL Server backup error 18204

If you have been facing the SQL Server backup error 18204, worry no more. Our experts have the solution.

This error pops up as a result of the operating system being unable to open or close a specific backup device that is part of a RESTORE or BACKUP command.

Here are some troubleshooting tips to resolve this issue:

1. First, we have to ensure the path in the RESTORE or BACKUP command is valid. We can do this by copy-pasting the path in Windows Explorer.
2. Next, try switching to a UNC if a mapped drive was specified in the command.
3. Then, ensure that the Windows account we used to start the SQL service has the necessary permissions for accessing the specified server. Furthermore, check if the account has permission to open the file for that particular operation.
4. After that, check if the file has been locked by another process or is marked as read-only.
5. Next, we can run tests to check if the problem is isolated to a specific file, path, or server.
6. Then, run hardware diagnostics to check if the media mentioned in the path is healthy or not.
7. In case the error returns only a number without any text, we can run NET HELPMSG in the command prompt to find the return text.

Furthermore, this fix has been fixed in these updates for SQL Server:

• Cumulative Update 13 for SQL Server 2017
• Cumulative Update 5 for SQL Server 2016 Service Pack 2
• Cumulative Update 13 for SQL Server 2016 Service Pack 1

Our experts recommend installing the latest build for the SQL server version to avoid running into the SQL Server backup error 18204.

[Need assistance with a different issue? Our team is available 24/7.]

Conclusion

In conclusion, our Support Engineers demonstrated how to troubleshoot SQL Server backup error 18204. Furthermore, we also learned that installing the latest build for our SQL version prevents this error from occurring.