Call now: 252-767-6166  
Oracle Training Oracle Support Development Oracle Apps

 
 Home
 E-mail Us
 Oracle Articles
New Oracle Articles


 Oracle Training
 Oracle Tips

 Oracle Forum
 Class Catalog


 Remote DBA
 Oracle Tuning
 Emergency 911
 RAC Support
 Apps Support
 Analysis
 Design
 Implementation
 Oracle Support


 SQL Tuning
 Security

 Oracle UNIX
 Oracle Linux
 Monitoring
 Remote s
upport
 Remote plans
 Remote
services
 Application Server

 Applications
 Oracle Forms
 Oracle Portal
 App Upgrades
 SQL Server
 Oracle Concepts
 Software Support

 Remote S
upport  
 Development  

 Implementation


 Consulting Staff
 Consulting Prices
 Help Wanted!

 


 Oracle Posters
 Oracle Books

 Oracle Scripts
 Ion
 Excel-DB  

Don Burleson Blog 


 

 

 


 

 

 
 
 

Oracle redo log corruption tips

Oracle Database Tips by Donald BurlesonJuly 27, 2015 - Updated 1/20/2016

Question:  I appear to have redo log corruption.  When when I try to start it it gives me the error:

ORA-01172: recovery of thread 1 stuck at block 25 of file 2
ORA-01151: use media recovery to recover block, restore backup if needed.

I think that the datafile that is corrupted is a redo log file, so is one of the redo log groups that is with the status "current" even that the database is in mount mode.

How do I repair redo log corruption?

Answer:  First, followthese staps to attempt a simple startup/recovery.

Next, perform a full backup of what you have now, before you proceed further.

Next, open a severity 1 service request on MOSC.  Check the oracle alert log & any trace files for more details regarding your message and datafile.

If the database is up and redo logs are available you could type RECOVER DATAFILE 2 and hit enter for now. If the database is hung, SHUTDOWN IMMEDIATE then STARTUP MOUNT, then RECOVER DATAFILE 2, then ALTER DATABASE OPEN. RECOVER DATABASE will check and recover all oracle datafiles and is fine too.

Once you are working with MOSC, they will assist you with techniques for repairing the corrupt data blocks.

When using undocumented parameters like _allow_resetlogs_corruption, YOU MUST do it WITH the assistance of Oracle tech support.

Oracle tech support may also be able to patch the corrupt blocks using the BBED utility.

Oracle Recovery with  _allow_resetlogs_corruption

Recovery of a database using the undocumented parameter _allow_resetlogs_corruption should be regarded as a last-ditch, emergency recovery scenario only, and should not be attempted until all other avenues of recovery have been exhausted.

Note that Oracle will not support a database that has been recovered using this method unless it is subsequently exported and rebuilt.

Essentially, using _allow_resetlogs_corruption forces the opening of the datafiles even if their SCNs do not match up; then, on the next checkpoint, the old SCN values are overwritten. This could leave the database in an unknown state as far as concurrency.

For additional information on handling corruption, see the BC expert notes on corruption and see MOSC Note 1088018.1 - Handling Oracle Database Corruption Issues.


 

 

��  
 
 
Oracle Training at Sea
 
 
 
 
oracle dba poster
 

 
Follow us on Twitter 
 
Oracle performance tuning software 
 
Oracle Linux poster
 
 
 

 

Burleson is the American Team

Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals.  Feel free to ask questions on our Oracle forum.

Verify experience! Anyone considering using the services of an Oracle support expert should independently investigate their credentials and experience, and not rely on advertisements and self-proclaimed expertise. All legitimate Oracle experts publish their Oracle qualifications.

Errata?  Oracle technology is changing and we strive to update our BC Oracle support information.  If you find an error or have a suggestion for improving our content, we would appreciate your feedback.  Just  e-mail:  

and include the URL for the page.


                    









Burleson Consulting

The Oracle of Database Support

Oracle Performance Tuning

Remote DBA Services


 

Copyright © 1996 -  2020

All rights reserved by Burleson

Oracle ® is the registered trademark of Oracle Corporation.