DB2 Log Chain

[#1]

Dear all,

happy new year ;o)

I have a question regarding db6.

Does anyone know where db2 stores information about the current log chain?   Is there a file ?

Thanks a lot for your help.

Best Regards,

Andreas

[Former Member · Accepted solution]

Hi Andreas,

Happy 2013 to you too.

The DB2 transaction log files have consecutive names from S00000000.LOG to S99999999.LOG.

If a log file is full, DB2 creates a new log file with the next number.

In some special cases DB2 can create log files with the same name but different contents - stored in different directories identified by the chain number.

As you probably know, log file chains are created if the database is restored to a point in time.

If you understand a retore was done, then you should find the log chain info in the directories where the logs are stored.

regards,

Javier

[Former Member · Accepted solution]

Good Morning Javier and Gaurav,

thanks for your responses.

I know why and when db2 creates log chains.

But do you know where db2 stores the information about log chains? Or how db2 calculates the next log chain? For example if I create a new database  and restore the db content from an backup image the current log chain e.g. 06 is created and not 00.  So I guess this information is stored in the backup image somewhere and maybe written into a file...

if yes do you know where?

Thanks again.

BR,

Andreas

[Former Member · Accepted solution]

Hello Andreas,

I guess you might be talking about log control file which is created under db2 database directory. Log control file contains information about active logs and the information is used during crash recovery.

You can refer to DB2 information center for more details.

Database directories and files

Log control files

Regards,

Masako

[former_member227150 · Accepted solution]

Hi Andreas,

Are you talking about control files in log directory.

Please check if below file is of any help.

/db2/<SID>/db2<sid>/NODE0000/SQL00001/SQLOGCTL.GLFH.1

This is log control file.

Let me know if any issue.

Regards,

Gaurav

[Former Member · Accepted solution]

Hi Gaurav,

thank you very much.

Yes it seems the log chain is stored in the log  header file.

Best Regards,

Andreas