Thinking About Virtual Log Files

Monica Rathbun has a reminder that Virtual Log Files can be troublesome in excess:

What causes High VLFs?

As transactions force growth of the log file, inappropriate log file sizing or auto-growth settings can cause a high number of VLFs to occur.  Each growth event adds VLFs to the log file.  The more often you grow in conjunction with smaller growth segments, the more VLFs your transaction log will have.

Example

If you grow your log by the default 1 MB you may end up with thousands of VLFs as opposed to growing by 1GB increments. MSDN does a great job on explaining how a transaction logs work for a deeper dive I recommend reading it.

Read on to see how many VLFs your databases have, as well as how to reduce the number should it grow excessive.

Related Posts

The SQLUndercover Inspector

Adrian Buckman announces the SQLUndercover Inspector: In a Nutshell: The SQLUndercover Inspector is a configurable daily report written in SQL that will send you an email (or log the report to a SQL Table) showing you information about specific parts of SQL Server in HTML format including highlighted warnings/advisory conditions, the report has configurable thresholds […]

Read More

Expanding LVM Drives

David Klee shows how to expand an LVM drive on Linux: Next in our SQL Server on Linux series is one important question. On Windows, if you’re about to run out of space, you get your VM admin / storage admin to expand one or more of your drives, and you go to Disk Management […]

Read More

Categories

August 2017
MTWTFSS
« Jul Sep »
 123456
78910111213
14151617181920
21222324252627
28293031