The Oracle (tm) Users' Co-Operative FAQ
How Do I Recover From Loss of a Active Redo Log Group?
| Author's name: Allan W. Tham
Author's Email: allanwtham@hotmail.com |
Date written: Feb 27 2002 Oracle version(s): 8.1.7.0.0 |
| This morning I found out that one of my redo log file went missing. I don't have multiplexing. I loss the only copy that I have. The database is halting now. What shall I do? |
Work for Archive Log Mode ON
1. To investigate what status is the missing redo log is -
a. select * from v$logfile shows which
group is INVALID
b. select * from v$log shows the status
of the invalid group
2. Now that you are confirmed that the lost redo file is an ACTIVE
redo log, shutdown the database - shutdown immediate
3. Restore the backup
4. Mount the database - Startup mount
5. If the media is corrupted where the default filesystem cannot
be written, move the file to other location -
a. In OS, find a directory to host the
new file and touch the file (same name)
b. alter database rename file
'/oldpath/filename.log' to '/newpath/filename.log'
If the original filesystem is good, skip
this step
6. Do a cancel based incomplete recovery -
a. recover database until cancel
b. Press Enter until you see ora-00308
and ora-27037
c. Rerun recover database until cancel
but type CANCEL at the prompt this time
7. Open the database and reset the logs - alter database open
resetlogs
8. Do a user managed backups of the entire database
9. DONE
(Note: All updates from the point of the incomplete recovery to
the present need to be re-executed!)
Further reading: Oracle9i User-Managed Backup and Recovery Guide
