As a SQL Server administrator, it is important to be familiar with the error messages that SQL Server throws. These error messages can provide valuable information about the issues that are causing problems in the system. In this blog post, we will discuss one such error message and how to troubleshoot it.

Recently, one of my readers reached out to me for help. He was a new hire fresh out of college and was having trouble starting the SQL Service. He shared the error message he was encountering:

Windows could not start the SQL Server (SQL2014) on Local Computer. For more information, review the System Event Log. If this is a non-Microsoft service, contact the service vendor, and refer to service-specific error code 3417.

Upon analyzing the error message, I realized that it wasn’t very helpful in identifying the root cause of the issue. I asked the reader to share the SQL Server ERRORLOG, which is a file that contains detailed information about the SQL Server instance.

For those who are not familiar with the ERRORLOG file, I directed the reader to my previous blog post titled “SQL SERVER – Where is ERRORLOG? Various Ways to Find its Location.” This blog post explains different methods to locate the ERRORLOG file.

After examining the ERRORLOG file, I found the following messages:

Starting up database 'master'.
Error: 5118, Severity: 16, State: 1.
The file "C:\Program Files\Microsoft SQL Server\MSSQL12.SQL2014\MSSQL\DATA\master.mdf" is compressed but does not reside in a read-only database or filegroup. The file must be decompressed.

Based on these messages, I asked the reader if any changes had been made to the “master.mdf” file. He confirmed that no changes had been made. However, upon further investigation, I discovered that the file was compressed, indicated by its blue color.

Compressed files can cause issues with SQL Server, as it requires the files to be decompressed in order to function properly. I instructed the reader to un-compress the “master.mdf” file, and after doing so, he was able to start the SQL Service successfully.

This incident serves as a reminder to never enable compression on folders containing SQL database files. Compressed files can lead to various errors and issues, as demonstrated in this case.

Have you ever encountered similar errors? Let me know in the comments below. It’s important to share our experiences and learn from each other’s mistakes to avoid such issues in the future.