Q: If I need to run the virus scanning software on a machine running SQL Server, what can I do without affecting performance?
A: The answer to this question depends on the type of virus scanning software you want to run. There are currently three types of virus scanning software: active virus scanning, virus removal, and vulnerability scanning.
Active Virus scanning software
We recommend that you use an active virus scan for the following SQL Server scenarios:
Run on the Internet.
Read and execute files from other servers.
Run an HTTP server, such as Microsoft Internet Information Services (IIS) or Apache. If you use XML for SQL Server (SQLXML) to access SQL Server over HTTP on IIS, it applies to your operating environment.
Host file sharing.
Use SQL Mail to process incoming and outgoing emails.
The main performance overhead is to open and close files. Although active virus scanning may cause significant performance loss on heavy-load machines, it is still recommended for security reasons.
Virus cleanup software
If the virus cleanup software has to scan SQL Server database files, SQL Server will cause performance degradation due to a large number of read operations on the I/O subsystem, especially on servers with a large number of files. If the software opens a file for scanning and you open SQL Server at the same time, the software marks the database as "suspicious", thus interrupting the database service.
It is worth noting that this type of software takes effect only after the virus has penetrated your hard disk. Therefore, it is best for your organization to adopt reliable security operations to prevent problems before they happen.
Vulnerability scan software
The vulnerability scan software is mainly for HTTP servers. This type of virus scan can effectively eliminate potential vulnerabilities. Microsoft did not notice any performance loss when using the vulnerability scan software.
