ORACLE undo tablespace

http://smartoracle.blogspot.com/2009/07/errors-ora-01552-ora-00376-ora-01110.html

Errors: ORA-01552 ORA-00376 ORA-01110 ORA-01548 –UNDO tablespace

Recently our Helpdesk people configured backup on Payroll server. while running the backup, backup applications locking the writing file.for that issue alert log showing errors like below:

Mon Jul 06 05:07:36 2009
KCF: write/open error block=0x6f6 online=1
file=2 D:\ORACLE9\PRODUCT\PAYROLL\ORADATA\PAYROLL9\UNDOTBS01.DBF
error=27072 txt: 'OSD-04008: WriteFile() failure, unable to write to file
O/S-Error: (OS 33) The process cannot access the file because another process has locked a portion of the file.'
Automatic datafile offline due to write error on
file 2: D:\ORACLE9\PRODUCT\PAYROLL\ORADATA\PAYROLL9\UNDOTBS01.DBF
Mon Jul 06 05:07:36 2009
Errors in file d:\oracle9\product\payroll\admin\payroll9\bdump\payroll9_smon_2700.trc:
ORA-00376: file 2 cannot be read at this time
ORA-01110: data file 2: 'D:\ORACLE9\PRODUCT\PAYROLL\ORADATA\PAYROLL9\UNDOTBS01.DBF'

Immediately we stopped the backup & restarted the database .
Still the Application is not working. Application show error message

"ORA-01552: cannot use system rollback segment for non-system tablespace"

then I checked for the corrupted rollback segments

SQL>select segment_name,status,tablespace_name from dba_rollback_segs where status='NEEDS RECOVERY';
SEGMENT_NAME STATUS TABLESPACE_NAME
------------------------------ ---------------- -----------------
_SYSSMU1$ NEEDS RECOVERY UNDOTBS1
_SYSSMU2$ NEEDS RECOVERY UNDOTBS1
_SYSSMU3$ NEEDS RECOVERY UNDOTBS1
_SYSSMU4$ NEEDS RECOVERY UNDOTBS1
_SYSSMU5$ NEEDS RECOVERY UNDOTBS1
_SYSSMU6$ NEEDS RECOVERY UNDOTBS1
_SYSSMU7$ NEEDS RECOVERY UNDOTBS1
_SYSSMU8$ NEEDS RECOVERY UNDOTBS1
_SYSSMU9$ NEEDS RECOVERY UNDOTBS1
_SYSSMU10$ NEEDS RECOVERY UNDOTBS1

then I recreated another tablespace as UNDOTBS2

CREATE UNDO TABLESPACE "UNDOTBS2"
DATAFILE 'D:\ORACLE9\PRODUCT\PAYROLL\ORADATA\PAYROLL9\UNDOTBS02.DBF' SIZE 200M REUSE
AUTOEXTEND ON NEXT 51200K MAXSIZE 800M;

ALTER SYSTEM SET undo_tablespace=UNDOTBS2 SCOPE=BOTH;

Now I try to drop the old UNDO tablespace but it’s giving error:

ora-01548 active rollback segment found

Now the issue is resolved but in Alert log we are getting errors like:

Wed Jul 15 11:50:52 2009
SMON: about to recover undo segment 1
SMON: mark undo segment 1 as needs recovery
……..
SMON: about to recover undo segment 10
SMON: mark undo segment 10 as needs recovery

& for some transactions from applications we are getting some more errors:

ORA-00376: file 2 cannot be read at this tme ORA-01110: data file 2: 'D:\ORACLE9\PRODUCT\PAYROLL\ORADATA\PAYROLL9\UNDOTBS01.DBF'

Solution:
1. create pfile from spfile;

2. Add the following line to pfile:

_corrupted_rollback_segments =('_SYSSMU1$','_SYSSMU2$','_SYSSMU3$','_SYSSMU4$',
'_SYSSMU5$','_SYSSMU6$','_SYSSMU7$','_SYSSMU8$','_SYSSMU9$','_SYSSMU10$')

_OFFLINE_ROLLBACK_SEGMENTS=('_SYSSMU1$','_SYSSMU2$','_SYSSMU3$','_SYSSMU4$','_SYSSMU5$','_SYSSMU6$','_SYSSMU7$','_SYSSMU8$','_SYSSMU9$','_SYSSMU10$')

3. comment undo management-Auto

#undo_management=AUTO

4. create spfile from pfile

5. Start the database again:

SQL> STARTUP RESTRICT

6. Drop bad rollback segments

SQL> drop rollback segment "_SYSSMU11$";
Rollback segment dropped.
......
SQL> drop rollback segment "_SYSSMU10$";
Rollback segment dropped.

7. Check again

SQL> select segment_name,status,tablespace_name from dba_rollback_segs where status='NEEDS RECOVERY';

No rows returned

8. DROP TABLESPACE undotbs1 INCLUDING CONTENTS AND DATAFILES ;

9. shutdown immedaite

10. remove added lines & comments from pfile and recreate the spfile

11.startup

Now the issue is resolved.