Click here to monitor SSC
SQLServerCentral is supported by Red Gate Software Ltd.
 
Log in  ::  Register  ::  Not logged in
 
 
 
        
Home       Members    Calendar    Who's On


Add to briefcase

Error log reports database log is truncated right before differential backup Expand / Collapse
Author
Message
Posted Wednesday, January 16, 2013 12:22 PM
SSC Journeyman

SSC JourneymanSSC JourneymanSSC JourneymanSSC JourneymanSSC JourneymanSSC JourneymanSSC JourneymanSSC Journeyman

Group: General Forum Members
Last Login: Tuesday, November 4, 2014 2:33 PM
Points: 93, Visits: 596
I've got a SQL Server 2000 system that has many databases in Full recovery with full, diff, and tlog backups. I'm seeing an unusual error that says "Database log truncated". It only shows as an error in the Application Event log. In the SQL Error log it doesn't show it as an error.

Here's the time sequence:
5AM Database log backup of db A
6AM Error: Database log truncated: Database: A
6:01AM Database differential changes backed up: Database: A
So my question is, how/why would the database log be truncated an hour after it has been backed up? I don't know if the Application Event log is erroneously reporting an error or if I have an actual problem.

Any help would be greatly appreciated!
Post #1408033
Posted Wednesday, January 16, 2013 12:44 PM


SSC-Insane

SSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-Insane

Group: General Forum Members
Last Login: Yesterday @ 11:32 PM
Points: 20,799, Visits: 32,718
Check the differential backup process for the database. It may have a truncate log in it just before the differential backup. Not something I'd want being done.



Lynn Pettis

For better assistance in answering your questions, click here
For tips to get better help with Performance Problems, click here
For Running Totals and its variations, click here or when working with partitioned tables
For more about Tally Tables, click here
For more about Cross Tabs and Pivots, click here and here
Managing Transaction Logs

SQL Musings from the Desert Fountain Valley SQL (My Mirror Blog)
Post #1408039
Posted Wednesday, January 16, 2013 12:48 PM


SSCertifiable

SSCertifiableSSCertifiableSSCertifiableSSCertifiableSSCertifiableSSCertifiableSSCertifiableSSCertifiableSSCertifiable

Group: General Forum Members
Last Login: Friday, November 21, 2014 7:42 AM
Points: 6,743, Visits: 8,515
- If the time interval is near constant, just start a sqlprofiler trace to capture all the needed and analyse it afterward.

- how are the backups being created at your systems ? SQLAgent scheduled jobs ?
check all sqlagent jobs to they don't contain a "backup log with truncate only" statement (we've seen that at some of our systems and had to contact the corresponding dev teams to clarify and remove them )

select J.name, suser_sname(J.owner_sid) as Owner, J.enabled, JS.*
from msdb..sysjobs J
inner join msdb..sysjobsteps JS
on JS.job_id = J.job_id
where JS.command like '%backup%truncate%'
order by Owner, name



Johan


Don't drive faster than your guardian angel can fly ...
but keeping both feet on the ground won't get you anywhere

- How to post Performance Problems
- How to post data/code to get the best help


- How to prevent a sore throat after hours of presenting ppt ?


"press F1 for solution", "press shift+F1 for urgent solution"


Need a bit of Powershell? How about this

Who am I ? Sometimes this is me but most of the time this is me
Post #1408042
Posted Wednesday, January 16, 2013 12:52 PM
SSC Journeyman

SSC JourneymanSSC JourneymanSSC JourneymanSSC JourneymanSSC JourneymanSSC JourneymanSSC JourneymanSSC Journeyman

Group: General Forum Members
Last Login: Tuesday, November 4, 2014 2:33 PM
Points: 93, Visits: 596
Thank you both. I found the issue. Our backup procedure was using Backup log @Database with truncate_only, which truncates the transaction log. Immediately after that it made a differential backup but the truncate_only would invalidate the previous log backups. We'll be fixing this today... Oi Vay!
Post #1408044
« Prev Topic | Next Topic »

Add to briefcase

Permissions Expand / Collapse