Monday

ORA-00376: file 6 cannot be read at this time

It seems each night I try to hit the sack a little early (1am) I get paged shortly after. Last night was no exception with a page coming in from one of our application support teams. Users in Australia were having issues logging into one of our customer support applications.

All of the environments I support are unix based but our team does support some Windows servers. So while i'm on call i'm responsible for those as well.

The first thing I do is check the alert log and I notice the following errors repeating over and over:

Errors in file d:\orant9i\admin\orcl\udump\orcl_j000_2096.trc:
ORA-12012: error on auto execute of job 22
ORA-00376: file 6 cannot be read at this time
ORA-01110: data file 6: 'D:\ORCL\MYDATA01.DBF'
ORA-06512: at "SCHEMA.STOREDPROCEDURE", line 3
ORA-06512: at line 1


I seemed to recall some of our other windows based database servers having issues in the past with backup software locking the files. So the next thing I do is called the Intel Support group in Australia and ask them if any backups were executed today. Indeed this past weekends full backups failed and they initiated some manual backups today.

The support person confirmed that the OS backup had completed, so I restarted the database. The database opened successfully and I checked the alert logs to verify there were no errors. As it had in the past occurrences, these steps resolved the issue.

Since I couldn't get back to sleep I kept an eye on the alert log and surfed the web on my home PC. About 20 minutes later the error appeared again followed by an email from a manager in Australia.

I was kind of surprised by this so I checked v$datafile. The status of 3 files was "RECOVER". My first thought was, why do I always get the fun issues when i'm on pager?!

This was a relatively small database and before I attempt any recovery I always take a cold backup. (If time allows.) Once I restarted the database I executed the following commands for each datafile that was marked as needing recovery:

SQL> recover datafile 'c:\my\datafile.dbf';
SQL> alter database datafile 'c:\my\datafile.dbf
' online;

Media recovery was successful and the problem did not reoccur. So just a note for those windows DBA's out there. If you have automated backup software ensure that your datafile directories are excluded. While on unix the worst case would be an inconsistent backup, on windows, file locking behaves differently and could cause an outage like the one I experienced.

Well, i'm off to bed shortly and hopefully will get a good nights sleep!

6 comments:

Anonymous said...

Freaking Awesome! Thank you, I dont know much about Oracle and have a couple of servers, the error started recently and your explaination was perfect and saved my bacon.

Anonymous said...

Also, after the recover, the datafiles can be in 'OFFLINE' mode after performing the step above... You need to do an alter database datafile ' ' online;

thanks
-Srinath

Anonymous said...

Thank you for posting this. I had the exact problem and you made my life easier. I hope you slept well that night.

Anonymous said...

Thank you!

Sridevi Koduru said...
This comment has been removed by the author.
Sridevi Koduru (Oracleappstechnical.com) said...

Regards
Sridevi Koduru (Senior Oracle Apps Trainer Oracleappstechnical.com)
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