SQL SERVER 2022 and Instant File Initialization for Log File

4 weeks ago

SQL Server 2022 (16.x) is the latest version of Microsoft’s relational database management system that offers several new features and enhancements to improve database performance and security. One such feature is instant file initialization (IFI), which allows data files to be created or extended without zero initialization, significantly reducing the time required for file growth events. This blog post will explore how Instant File Initialization for Log File growth events in SQL Server 2022.

What is Instant File Initialization?

IFI is a feature in SQL Server that enables faster file growth events by bypassing the zero initialization process for data files. When a new data file is created, or an existing data file is extended, SQL Server can immediately use the available disk space without waiting for the zero initialization process to complete. This results in significant time savings and improved database performance.

SQL Server 2022 and IFI

In general, transaction log files cannot benefit from IFI, as they contain critical information that must be written to disk immediately. However, in SQL Server 2022 (16.x) and Azure SQL Database, IFI can benefit transaction log growth events up to 64 MB. The default auto-growth size increment for new databases is also 64 MB, which means that most transaction log file auto-growth events can benefit from IFI. For example, if the transaction log file is 128 MB and needs to grow by 64 MB, IFI can allocate the new space without zero initialization. However, if the transaction log file needs to grow by more than 64 MB, IFI cannot be used, and zero initialization must be performed.

Enabling Instant File Initialization

To allow IFI for SQL Server 2022, the SQL Server service account must be granted the Perform Volume Maintenance Tasks (PVMT) security privilege. This privilege allows the SQL Server service account to bypass the zero initialization process and allocate disk space immediately. However, enabling IFI can have security implications, allowing the SQL Server service account to directly access disk sectors without zero initialization. Therefore, granting the PVMT privilege only to trusted service accounts is recommended.

Here are my previous articles on this topic, which you may find interesting:

Conclusion

Instant file initialization is a powerful feature in SQL Server 2022 that can significantly reduce the time required for file growth events, including transaction log file growth events up to 64 MB. By adequately utilizing IFI, database administrators can improve database performance and reduce the impact of file growth events on the overall system. You can always connect with me on Twitter.

Reference: Pinal Dave (http://blog.SQLAuthority.com)