https://www.sqlserver70.com/tags/virtual-log-files/Recent content in Virtual Log Files on SQL Server ScriptsHugo -- gohugo.ioenSQLServer70.comMon, 18 May 2026 00:00:00 +0000https://www.sqlserver70.com/post/sql-server-vlf-count-report/Mon, 18 May 2026 00:00:00 +0000https://www.sqlserver70.com/post/sql-server-vlf-count-report/ <p>Excessive virtual log files (VLFs) inside the transaction log slow down database recovery, backup, and restore operations — often by minutes on large logs — and the problem compounds silently every time autogrowth fires with a small increment. This script queries DBCC LOGINFO across every online database on the instance, counts VLFs and active VLFs per database, and assigns a health assessment so DBAs can prioritize remediation.</p> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-1012089347386563" crossorigin="anonymous"></script> <ins class="adsbygoogle" style="display:inline-block;width:728px;height:90px" data-ad-client="ca-pub-1012089347386563" data-ad-slot="8593449130"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> <h2 id="purpose-and-overview">Purpose and Overview</h2> <p>A SQL Server transaction log is internally divided into virtual log files. SQL Server creates VLFs automatically when the log file grows, and the number of VLFs per growth event depends on the size of the growth increment — small increments create fewer but more numerous VLFs over time, while a single large pre-allocation creates just a handful. When a log accumulates hundreds or thousands of VLFs, SQL Server must scan every VLF header during recovery, log backup, and restore, adding overhead that scales linearly with VLF count. Paul S. Randal of SQLskills.com documented the authoritative research on VLF overhead and the recommended thresholds in his foundational VLF series.</p>