Full backup not emptying transaction log

SQLServerCentral is supported by Red Gate Software Ltd.

Popular Topics

Home

Members

Calendar

Who's On

Home » SQL Server 2008 » SQL Server 2008 Administration » Full backup not emptying transaction log

Full backup not emptying transaction log

Rate Topic

Display Mode

Topic Options

Author

Message

ngreene

Posted Thursday, November 08, 2012 6:39 AM

Grasshopper

Group: General Forum Members
Last Login: Tuesday, June 11, 2013 8:35 AM
Points: 18, Visits: 265

I have a database that process a lot of transaction late at night. It is set to full recovery mode. Every night I do a full backup of the database, but the log file does not empty out. It just continues to grow and never seems to release old transactions after a backup. As a quick fix, which i don't like, I will temporarily switch recovery mode to simple->truncate log file->set recovery mode to full->then full backup of database. Any ideas why the transaction log does not empty out after a full backup and continues to grow?

thanks

Post #1382464

anthony.green

Posted Thursday, November 08, 2012 6:47 AM

SSCertifiable

Group: General Forum Members
Last Login: Wednesday, June 05, 2013 2:40 AM
Points: 5,075, Visits: 4,833

A full backup doesn't backup the transaction log, you need to take regular transaction log backups to make the log re-usable and stop it from growing out of control.

Managing Transaction Logs - http://www.sqlservercentral.com/articles/Administration/64582/

Stairway to Transaction Log Management - http://www.sqlservercentral.com/stairway/73776/

Want an answer fast? Try here
How to post data/code for the best help - Jeff Moden
Need a string splitter, try this - Jeff Moden
How to post performance problems - Gail Shaw
CrossTabs-Part1 & Part2 - Jeff Moden
SQL Server Backup, Integrity Check, and Index and Statistics Maintenance - Ola Hallengren
Managing Transaction Logs - Gail Shaw
Troubleshooting SQL Server: A Guide for the Accidental DBA - Jonathan Kehayias and Ted Krueger

Post #1382467

George M Parker

Posted Thursday, November 08, 2012 7:03 AM

Mr or Mrs. 500

Group: General Forum Members
Last Login: Wednesday, June 12, 2013 2:44 PM
Points: 526, Visits: 1,007

I recommend you read Paul Randal's blog about backup myths: http://sqlskills.com/blogs/paul/post/A-SQL-Server-DBA-myth-a-day-(3030)-backup-myths.aspx

30-05) a full or differential backup clears the log

No. A log backup includes all the log since the last log backup - nothing can change that - no matter whether that log was also backed up by a full or differential backup. I had a famous argument on Twitter last year and wrote this blog post as proof: Misconceptions around the log and log backups: how to convince yourself. In the FULL or BULK_LOGGED recovery models, the *only* thing that clears the log is a log backup.

Post #1382472

GilaMonster

Posted Thursday, November 08, 2012 9:11 AM

SSC-Dedicated

Group: General Forum Members
Last Login: Today @ 4:18 PM
Points: 38,062, Visits: 30,359

If you're not taking log backups for point-in-time restore capability, why is the DB in full recovery model in the first place?

Gail Shaw
Microsoft Certified Master: SQL Server 2008, MVP
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

Post #1382561

« Prev Topic | Next Topic »

Permissions