Recently we faced an issue that SQL Server was not coming up online in one of our environment.

We found below error messages in Windows application event logs:

Open failed: Could not open file E:\TempDB\tempdb.mdf for file number 1. OS error: 32(The process cannot access the file because it is being used by another process.).
Unable to open the physical file "E:\TempDB\tempdb.mdf". Operating system error 32: "32(The process cannot access the file because it is being used by another process.)".
CREATE DATABASE failed. Some file names listed could not be created.

As we have a clear message, while SQL Service starts, it was not able to create the TEMPDB as the mdf file is being used by another process.
When it happens, it will not start the SQL Service even we manually start it through services.msc. However, we identified, the service will come online once we restart the server.

We started our investigation verifying whether more than one instances are pointing to the same directory for TEMPDB files. Though we have multiple instances on the environment, we made it sure those instances are configured separately and properly. Once we confirmed the SQL Server configuration, we took our attention to other services especially with AntiVirus services. We found that there is Mcafee software running, but unfortunately, we could not find any reference on ProcessExplorer as well. However, we decided to stop the McAfee and see if the issue is related to the AnitVirus scan. Now, it is almost more than two weeks and we did not experience the issue.

Takeaway, if you find similar issue, Instead of disabling or stopping the services related Antivirus, we can exclude certain files associated with SQL Server from the scan.

Here are few directories that can be excluded from anti-virus scanning tool:

1. C:\Windows\System32\LogFiles
2. C:\Windows\System64\LogFiles
3. C:\windows\System32\GroupPolicy\
4. C:\windows\temp
5. C:\windows\SoftwareDistribution\Datastore
6. C:\windows\SoftwareDistribution\Datastore\Logs
7. C:\\Temporary ASP.NET Files
8. C:\Users\\AppData\Local\Temp
9. C:\Users\Default\AppData\Local\Temp
10. C:\ProgramData\Microsoft\SQL Server
11. C:\Program Files\Microsoft SQL Server
12. Exclude SQL Server Data Files (*.MDF, *.LDF, *.NDF)
13. Exclude SQL Server Backup Files (*.TRN, *.BAK)
14. Exclude Full-Text Catalog Files (*.SLS)
15. Exclude sqlmangr.exe
16. Exclude sqlservr.exe

Please give your feedback if this post helps you!!!