Description
Occurs during while SQL Server is waiting for the Operating System to complete file system requests. This happens for operations such as backup, restore, file initialization (creation and growth), dropping files, etc. Small to moderate values are expected and acceptable. Excessive values should be investigated
Resolved by
DBAs and Developers
Suggested solutions
- Enable Perform Volume Maintenance Tasks to avoid zero-initialisation for data files
- Investigate storage issues in the Windows Event Viewer
- Ensure storage drivers are up to date
Additional research
What’s in PREEMPTIVE_OS_FILEOPS wait type?
PREEMPTIVE and Non-PREEMPTIVE
Improving SQL Server Performance by using Instant File Initialization